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tmp_suning_uos_patched/drivers/usb/host/ehci-sched.c
Sarah Sharp dccd574ccc USB: ehci: Respect IST when scheduling new split iTDs. 
The EHCI specification says that an EHCI host controller may cache part of
the isochronous schedule.  The EHCI controller must advertise how much it
caches in the schedule through the HCCPARAMS register isochronous
scheduling threshold (IST) bits.

In theory, adding new iTDs within the IST should be harmless.  The HW will
follow the old cached linked list and miss the new iTD.  SW will notice HW
missed the iTD and return 0 for the transfer length.

However, Intel ICH9 chipsets (and some later chipsets) have issues when SW
attempts to schedule a split transaction within the IST.  All transfers
will cease being sent out that port, and the drivers will see isochronous
packets complete with a length of zero.  Start of frames may or may not
also disappear, causing the device to go into auto-suspend.  This "bus
stall" will continue until a control or bulk transfer is queued to a
device under that roothub.

Most drivers will never cause this behavior, because they use multiple
URBs with multiple packets to keep the bus busy.  If you limit the number
of URBs to one, you may be able to hit this bug.

Make sure the EHCI driver does not schedule full-speed transfers within
the IST under an Intel chipset.  Make sure that when we fall behind the
current microframe plus IST, we schedule the new transfer at the next
periodic interval after the IST.

Don't change the scheduling for new transfers, since the schedule slop will
always be greater than the IST.  Allow high speed isochronous transfers to
be scheduled within the IST, since this doesn't trigger the Intel chipset
bug.

Make sure that if the host caches the full frame, the EHCI driver's
internal isochronous threshold (ehci->i_thresh) is set to
8 microframes + 2 microframes wiggle room.  This is similar to what is done in
the case where the host caches less than the full frame.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:55:18 -08:00

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/*
* Copyright (c) 2001-2004 by David Brownell
* Copyright (c) 2003 Michal Sojka, for high-speed iso transfers
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* this file is part of ehci-hcd.c */
/*-------------------------------------------------------------------------*/
/*
* EHCI scheduled transaction support: interrupt, iso, split iso
* These are called "periodic" transactions in the EHCI spec.
*
* Note that for interrupt transfers, the QH/QTD manipulation is shared
* with the "asynchronous" transaction support (control/bulk transfers).
* The only real difference is in how interrupt transfers are scheduled.
*
* For ISO, we make an "iso_stream" head to serve the same role as a QH.
* It keeps track of every ITD (or SITD) that's linked, and holds enough
* pre-calculated schedule data to make appending to the queue be quick.
*/
static int ehci_get_frame (struct usb_hcd *hcd);
/*-------------------------------------------------------------------------*/
/*
* periodic_next_shadow - return "next" pointer on shadow list
* @periodic: host pointer to qh/itd/sitd
* @tag: hardware tag for type of this record
*/
static union ehci_shadow *
periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
__hc32 tag)
{
switch (hc32_to_cpu(ehci, tag)) {
case Q_TYPE_QH:
return &periodic->qh->qh_next;
case Q_TYPE_FSTN:
return &periodic->fstn->fstn_next;
case Q_TYPE_ITD:
return &periodic->itd->itd_next;
// case Q_TYPE_SITD:
default:
return &periodic->sitd->sitd_next;
}
}
static __hc32 *
shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
__hc32 tag)
{
switch (hc32_to_cpu(ehci, tag)) {
/* our ehci_shadow.qh is actually software part */
case Q_TYPE_QH:
return &periodic->qh->hw->hw_next;
/* others are hw parts */
default:
return periodic->hw_next;
}
}
/* caller must hold ehci->lock */
static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
{
union ehci_shadow *prev_p = &ehci->pshadow[frame];
__hc32 *hw_p = &ehci->periodic[frame];
union ehci_shadow here = *prev_p;
/* find predecessor of "ptr"; hw and shadow lists are in sync */
while (here.ptr && here.ptr != ptr) {
prev_p = periodic_next_shadow(ehci, prev_p,
Q_NEXT_TYPE(ehci, *hw_p));
hw_p = shadow_next_periodic(ehci, &here,
Q_NEXT_TYPE(ehci, *hw_p));
here = *prev_p;
}
/* an interrupt entry (at list end) could have been shared */
if (!here.ptr)
return;
/* update shadow and hardware lists ... the old "next" pointers
* from ptr may still be in use, the caller updates them.
*/
*prev_p = *periodic_next_shadow(ehci, &here,
Q_NEXT_TYPE(ehci, *hw_p));
*hw_p = *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p));
}
/* how many of the uframe's 125 usecs are allocated? */
static unsigned short
periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
{
__hc32 *hw_p = &ehci->periodic [frame];
union ehci_shadow *q = &ehci->pshadow [frame];
unsigned usecs = 0;
struct ehci_qh_hw *hw;
while (q->ptr) {
switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
case Q_TYPE_QH:
hw = q->qh->hw;
/* is it in the S-mask? */
if (hw->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
usecs += q->qh->usecs;
/* ... or C-mask? */
if (hw->hw_info2 & cpu_to_hc32(ehci,
1 << (8 + uframe)))
usecs += q->qh->c_usecs;
hw_p = &hw->hw_next;
q = &q->qh->qh_next;
break;
// case Q_TYPE_FSTN:
default:
/* for "save place" FSTNs, count the relevant INTR
* bandwidth from the previous frame
*/
if (q->fstn->hw_prev != EHCI_LIST_END(ehci)) {
ehci_dbg (ehci, "ignoring FSTN cost ...\n");
}
hw_p = &q->fstn->hw_next;
q = &q->fstn->fstn_next;
break;
case Q_TYPE_ITD:
if (q->itd->hw_transaction[uframe])
usecs += q->itd->stream->usecs;
hw_p = &q->itd->hw_next;
q = &q->itd->itd_next;
break;
case Q_TYPE_SITD:
/* is it in the S-mask? (count SPLIT, DATA) */
if (q->sitd->hw_uframe & cpu_to_hc32(ehci,
1 << uframe)) {
if (q->sitd->hw_fullspeed_ep &
cpu_to_hc32(ehci, 1<<31))
usecs += q->sitd->stream->usecs;
else /* worst case for OUT start-split */
usecs += HS_USECS_ISO (188);
}
/* ... C-mask? (count CSPLIT, DATA) */
if (q->sitd->hw_uframe &
cpu_to_hc32(ehci, 1 << (8 + uframe))) {
/* worst case for IN complete-split */
usecs += q->sitd->stream->c_usecs;
}
hw_p = &q->sitd->hw_next;
q = &q->sitd->sitd_next;
break;
}
}
#ifdef DEBUG
if (usecs > 100)
ehci_err (ehci, "uframe %d sched overrun: %d usecs\n",
frame * 8 + uframe, usecs);
#endif
return usecs;
}
/*-------------------------------------------------------------------------*/
static int same_tt (struct usb_device *dev1, struct usb_device *dev2)
{
if (!dev1->tt || !dev2->tt)
return 0;
if (dev1->tt != dev2->tt)
return 0;
if (dev1->tt->multi)
return dev1->ttport == dev2->ttport;
else
return 1;
}
#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
/* Which uframe does the low/fullspeed transfer start in?
*
* The parameter is the mask of ssplits in "H-frame" terms
* and this returns the transfer start uframe in "B-frame" terms,
* which allows both to match, e.g. a ssplit in "H-frame" uframe 0
* will cause a transfer in "B-frame" uframe 0. "B-frames" lag
* "H-frames" by 1 uframe. See the EHCI spec sec 4.5 and figure 4.7.
*/
static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask)
{
unsigned char smask = QH_SMASK & hc32_to_cpu(ehci, mask);
if (!smask) {
ehci_err(ehci, "invalid empty smask!\n");
/* uframe 7 can't have bw so this will indicate failure */
return 7;
}
return ffs(smask) - 1;
}
static const unsigned char
max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
/* carryover low/fullspeed bandwidth that crosses uframe boundries */
static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
{
int i;
for (i=0; i<7; i++) {
if (max_tt_usecs[i] < tt_usecs[i]) {
tt_usecs[i+1] += tt_usecs[i] - max_tt_usecs[i];
tt_usecs[i] = max_tt_usecs[i];
}
}
}
/* How many of the tt's periodic downstream 1000 usecs are allocated?
*
* While this measures the bandwidth in terms of usecs/uframe,
* the low/fullspeed bus has no notion of uframes, so any particular
* low/fullspeed transfer can "carry over" from one uframe to the next,
* since the TT just performs downstream transfers in sequence.
*
* For example two separate 100 usec transfers can start in the same uframe,
* and the second one would "carry over" 75 usecs into the next uframe.
*/
static void
periodic_tt_usecs (
struct ehci_hcd *ehci,
struct usb_device *dev,
unsigned frame,
unsigned short tt_usecs[8]
)
{
__hc32 *hw_p = &ehci->periodic [frame];
union ehci_shadow *q = &ehci->pshadow [frame];
unsigned char uf;
memset(tt_usecs, 0, 16);
while (q->ptr) {
switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
case Q_TYPE_ITD:
hw_p = &q->itd->hw_next;
q = &q->itd->itd_next;
continue;
case Q_TYPE_QH:
if (same_tt(dev, q->qh->dev)) {
uf = tt_start_uframe(ehci, q->qh->hw->hw_info2);
tt_usecs[uf] += q->qh->tt_usecs;
}
hw_p = &q->qh->hw->hw_next;
q = &q->qh->qh_next;
continue;
case Q_TYPE_SITD:
if (same_tt(dev, q->sitd->urb->dev)) {
uf = tt_start_uframe(ehci, q->sitd->hw_uframe);
tt_usecs[uf] += q->sitd->stream->tt_usecs;
}
hw_p = &q->sitd->hw_next;
q = &q->sitd->sitd_next;
continue;
// case Q_TYPE_FSTN:
default:
ehci_dbg(ehci, "ignoring periodic frame %d FSTN\n",
frame);
hw_p = &q->fstn->hw_next;
q = &q->fstn->fstn_next;
}
}
carryover_tt_bandwidth(tt_usecs);
if (max_tt_usecs[7] < tt_usecs[7])
ehci_err(ehci, "frame %d tt sched overrun: %d usecs\n",
frame, tt_usecs[7] - max_tt_usecs[7]);
}
/*
* Return true if the device's tt's downstream bus is available for a
* periodic transfer of the specified length (usecs), starting at the
* specified frame/uframe. Note that (as summarized in section 11.19
* of the usb 2.0 spec) TTs can buffer multiple transactions for each
* uframe.
*
* The uframe parameter is when the fullspeed/lowspeed transfer
* should be executed in "B-frame" terms, which is the same as the
* highspeed ssplit's uframe (which is in "H-frame" terms). For example
* a ssplit in "H-frame" 0 causes a transfer in "B-frame" 0.
* See the EHCI spec sec 4.5 and fig 4.7.
*
* This checks if the full/lowspeed bus, at the specified starting uframe,
* has the specified bandwidth available, according to rules listed
* in USB 2.0 spec section 11.18.1 fig 11-60.
*
* This does not check if the transfer would exceed the max ssplit
* limit of 16, specified in USB 2.0 spec section 11.18.4 requirement #4,
* since proper scheduling limits ssplits to less than 16 per uframe.
*/
static int tt_available (
struct ehci_hcd *ehci,
unsigned period,
struct usb_device *dev,
unsigned frame,
unsigned uframe,
u16 usecs
)
{
if ((period == 0) || (uframe >= 7)) /* error */
return 0;
for (; frame < ehci->periodic_size; frame += period) {
unsigned short tt_usecs[8];
periodic_tt_usecs (ehci, dev, frame, tt_usecs);
ehci_vdbg(ehci, "tt frame %d check %d usecs start uframe %d in"
" schedule %d/%d/%d/%d/%d/%d/%d/%d\n",
frame, usecs, uframe,
tt_usecs[0], tt_usecs[1], tt_usecs[2], tt_usecs[3],
tt_usecs[4], tt_usecs[5], tt_usecs[6], tt_usecs[7]);
if (max_tt_usecs[uframe] <= tt_usecs[uframe]) {
ehci_vdbg(ehci, "frame %d uframe %d fully scheduled\n",
frame, uframe);
return 0;
}
/* special case for isoc transfers larger than 125us:
* the first and each subsequent fully used uframe
* must be empty, so as to not illegally delay
* already scheduled transactions
*/
if (125 < usecs) {
int ufs = (usecs / 125);
int i;
for (i = uframe; i < (uframe + ufs) && i < 8; i++)
if (0 < tt_usecs[i]) {
ehci_vdbg(ehci,
"multi-uframe xfer can't fit "
"in frame %d uframe %d\n",
frame, i);
return 0;
}
}
tt_usecs[uframe] += usecs;
carryover_tt_bandwidth(tt_usecs);
/* fail if the carryover pushed bw past the last uframe's limit */
if (max_tt_usecs[7] < tt_usecs[7]) {
ehci_vdbg(ehci,
"tt unavailable usecs %d frame %d uframe %d\n",
usecs, frame, uframe);
return 0;
}
}
return 1;
}
#else
/* return true iff the device's transaction translator is available
* for a periodic transfer starting at the specified frame, using
* all the uframes in the mask.
*/
static int tt_no_collision (
struct ehci_hcd *ehci,
unsigned period,
struct usb_device *dev,
unsigned frame,
u32 uf_mask
)
{
if (period == 0) /* error */
return 0;
/* note bandwidth wastage: split never follows csplit
* (different dev or endpoint) until the next uframe.
* calling convention doesn't make that distinction.
*/
for (; frame < ehci->periodic_size; frame += period) {
union ehci_shadow here;
__hc32 type;
struct ehci_qh_hw *hw;
here = ehci->pshadow [frame];
type = Q_NEXT_TYPE(ehci, ehci->periodic [frame]);
while (here.ptr) {
switch (hc32_to_cpu(ehci, type)) {
case Q_TYPE_ITD:
type = Q_NEXT_TYPE(ehci, here.itd->hw_next);
here = here.itd->itd_next;
continue;
case Q_TYPE_QH:
hw = here.qh->hw;
if (same_tt (dev, here.qh->dev)) {
u32 mask;
mask = hc32_to_cpu(ehci,
hw->hw_info2);
/* "knows" no gap is needed */
mask |= mask >> 8;
if (mask & uf_mask)
break;
}
type = Q_NEXT_TYPE(ehci, hw->hw_next);
here = here.qh->qh_next;
continue;
case Q_TYPE_SITD:
if (same_tt (dev, here.sitd->urb->dev)) {
u16 mask;
mask = hc32_to_cpu(ehci, here.sitd
->hw_uframe);
/* FIXME assumes no gap for IN! */
mask |= mask >> 8;
if (mask & uf_mask)
break;
}
type = Q_NEXT_TYPE(ehci, here.sitd->hw_next);
here = here.sitd->sitd_next;
continue;
// case Q_TYPE_FSTN:
default:
ehci_dbg (ehci,
"periodic frame %d bogus type %d\n",
frame, type);
}
/* collision or error */
return 0;
}
}
/* no collision */
return 1;
}
#endif /* CONFIG_USB_EHCI_TT_NEWSCHED */
/*-------------------------------------------------------------------------*/
static int enable_periodic (struct ehci_hcd *ehci)
{
u32 cmd;
int status;
if (ehci->periodic_sched++)
return 0;
/* did clearing PSE did take effect yet?
* takes effect only at frame boundaries...
*/
status = handshake_on_error_set_halt(ehci, &ehci->regs->status,
STS_PSS, 0, 9 * 125);
if (status)
return status;
cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE;
ehci_writel(ehci, cmd, &ehci->regs->command);
/* posted write ... PSS happens later */
ehci_to_hcd(ehci)->state = HC_STATE_RUNNING;
/* make sure ehci_work scans these */
ehci->next_uframe = ehci_readl(ehci, &ehci->regs->frame_index)
% (ehci->periodic_size << 3);
if (unlikely(ehci->broken_periodic))
ehci->last_periodic_enable = ktime_get_real();
return 0;
}
static int disable_periodic (struct ehci_hcd *ehci)
{
u32 cmd;
int status;
if (--ehci->periodic_sched)
return 0;
if (unlikely(ehci->broken_periodic)) {
/* delay experimentally determined */
ktime_t safe = ktime_add_us(ehci->last_periodic_enable, 1000);
ktime_t now = ktime_get_real();
s64 delay = ktime_us_delta(safe, now);
if (unlikely(delay > 0))
udelay(delay);
}
/* did setting PSE not take effect yet?
* takes effect only at frame boundaries...
*/
status = handshake_on_error_set_halt(ehci, &ehci->regs->status,
STS_PSS, STS_PSS, 9 * 125);
if (status)
return status;
cmd = ehci_readl(ehci, &ehci->regs->command) & ~CMD_PSE;
ehci_writel(ehci, cmd, &ehci->regs->command);
/* posted write ... */
ehci->next_uframe = -1;
return 0;
}
/*-------------------------------------------------------------------------*/
/* periodic schedule slots have iso tds (normal or split) first, then a
* sparse tree for active interrupt transfers.
*
* this just links in a qh; caller guarantees uframe masks are set right.
* no FSTN support (yet; ehci 0.96+)
*/
static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
{
unsigned i;
unsigned period = qh->period;
dev_dbg (&qh->dev->dev,
"link qh%d-%04x/%p start %d [%d/%d us]\n",
period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
& (QH_CMASK | QH_SMASK),
qh, qh->start, qh->usecs, qh->c_usecs);
/* high bandwidth, or otherwise every microframe */
if (period == 0)
period = 1;
for (i = qh->start; i < ehci->periodic_size; i += period) {
union ehci_shadow *prev = &ehci->pshadow[i];
__hc32 *hw_p = &ehci->periodic[i];
union ehci_shadow here = *prev;
__hc32 type = 0;
/* skip the iso nodes at list head */
while (here.ptr) {
type = Q_NEXT_TYPE(ehci, *hw_p);
if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
break;
prev = periodic_next_shadow(ehci, prev, type);
hw_p = shadow_next_periodic(ehci, &here, type);
here = *prev;
}
/* sorting each branch by period (slow-->fast)
* enables sharing interior tree nodes
*/
while (here.ptr && qh != here.qh) {
if (qh->period > here.qh->period)
break;
prev = &here.qh->qh_next;
hw_p = &here.qh->hw->hw_next;
here = *prev;
}
/* link in this qh, unless some earlier pass did that */
if (qh != here.qh) {
qh->qh_next = here;
if (here.qh)
qh->hw->hw_next = *hw_p;
wmb ();
prev->qh = qh;
*hw_p = QH_NEXT (ehci, qh->qh_dma);
}
}
qh->qh_state = QH_STATE_LINKED;
qh->xacterrs = 0;
qh_get (qh);
/* update per-qh bandwidth for usbfs */
ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->period
? ((qh->usecs + qh->c_usecs) / qh->period)
: (qh->usecs * 8);
/* maybe enable periodic schedule processing */
return enable_periodic(ehci);
}
static int qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
unsigned i;
unsigned period;
// FIXME:
// IF this isn't high speed
// and this qh is active in the current uframe
// (and overlay token SplitXstate is false?)
// THEN
// qh->hw_info1 |= cpu_to_hc32(1 << 7 /* "ignore" */);
/* high bandwidth, or otherwise part of every microframe */
if ((period = qh->period) == 0)
period = 1;
for (i = qh->start; i < ehci->periodic_size; i += period)
periodic_unlink (ehci, i, qh);
/* update per-qh bandwidth for usbfs */
ehci_to_hcd(ehci)->self.bandwidth_allocated -= qh->period
? ((qh->usecs + qh->c_usecs) / qh->period)
: (qh->usecs * 8);
dev_dbg (&qh->dev->dev,
"unlink qh%d-%04x/%p start %d [%d/%d us]\n",
qh->period,
hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
qh, qh->start, qh->usecs, qh->c_usecs);
/* qh->qh_next still "live" to HC */
qh->qh_state = QH_STATE_UNLINK;
qh->qh_next.ptr = NULL;
qh_put (qh);
/* maybe turn off periodic schedule */
return disable_periodic(ehci);
}
static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
{
unsigned wait;
struct ehci_qh_hw *hw = qh->hw;
int rc;
/* If the QH isn't linked then there's nothing we can do
* unless we were called during a giveback, in which case
* qh_completions() has to deal with it.
*/
if (qh->qh_state != QH_STATE_LINKED) {
if (qh->qh_state == QH_STATE_COMPLETING)
qh->needs_rescan = 1;
return;
}
qh_unlink_periodic (ehci, qh);
/* simple/paranoid: always delay, expecting the HC needs to read
* qh->hw_next or finish a writeback after SPLIT/CSPLIT ... and
* expect khubd to clean up after any CSPLITs we won't issue.
* active high speed queues may need bigger delays...
*/
if (list_empty (&qh->qtd_list)
|| (cpu_to_hc32(ehci, QH_CMASK)
& hw->hw_info2) != 0)
wait = 2;
else
wait = 55; /* worst case: 3 * 1024 */
udelay (wait);
qh->qh_state = QH_STATE_IDLE;
hw->hw_next = EHCI_LIST_END(ehci);
wmb ();
qh_completions(ehci, qh);
/* reschedule QH iff another request is queued */
if (!list_empty(&qh->qtd_list) &&
HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
rc = qh_schedule(ehci, qh);
/* An error here likely indicates handshake failure
* or no space left in the schedule. Neither fault
* should happen often ...
*
* FIXME kill the now-dysfunctional queued urbs
*/
if (rc != 0)
ehci_err(ehci, "can't reschedule qh %p, err %d\n",
qh, rc);
}
}
/*-------------------------------------------------------------------------*/
static int check_period (
struct ehci_hcd *ehci,
unsigned frame,
unsigned uframe,
unsigned period,
unsigned usecs
) {
int claimed;
/* complete split running into next frame?
* given FSTN support, we could sometimes check...
*/
if (uframe >= 8)
return 0;
/*
* 80% periodic == 100 usec/uframe available
* convert "usecs we need" to "max already claimed"
*/
usecs = 100 - usecs;
/* we "know" 2 and 4 uframe intervals were rejected; so
* for period 0, check _every_ microframe in the schedule.
*/
if (unlikely (period == 0)) {
do {
for (uframe = 0; uframe < 7; uframe++) {
claimed = periodic_usecs (ehci, frame, uframe);
if (claimed > usecs)
return 0;
}
} while ((frame += 1) < ehci->periodic_size);
/* just check the specified uframe, at that period */
} else {
do {
claimed = periodic_usecs (ehci, frame, uframe);
if (claimed > usecs)
return 0;
} while ((frame += period) < ehci->periodic_size);
}
// success!
return 1;
}
static int check_intr_schedule (
struct ehci_hcd *ehci,
unsigned frame,
unsigned uframe,
const struct ehci_qh *qh,
__hc32 *c_maskp
)
{
int retval = -ENOSPC;
u8 mask = 0;
if (qh->c_usecs && uframe >= 6) /* FSTN territory? */
goto done;
if (!check_period (ehci, frame, uframe, qh->period, qh->usecs))
goto done;
if (!qh->c_usecs) {
retval = 0;
*c_maskp = 0;
goto done;
}
#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
if (tt_available (ehci, qh->period, qh->dev, frame, uframe,
qh->tt_usecs)) {
unsigned i;
/* TODO : this may need FSTN for SSPLIT in uframe 5. */
for (i=uframe+1; i<8 && i<uframe+4; i++)
if (!check_period (ehci, frame, i,
qh->period, qh->c_usecs))
goto done;
else
mask |= 1 << i;
retval = 0;
*c_maskp = cpu_to_hc32(ehci, mask << 8);
}
#else
/* Make sure this tt's buffer is also available for CSPLITs.
* We pessimize a bit; probably the typical full speed case
* doesn't need the second CSPLIT.
*
* NOTE: both SPLIT and CSPLIT could be checked in just
* one smart pass...
*/
mask = 0x03 << (uframe + qh->gap_uf);
*c_maskp = cpu_to_hc32(ehci, mask << 8);
mask |= 1 << uframe;
if (tt_no_collision (ehci, qh->period, qh->dev, frame, mask)) {
if (!check_period (ehci, frame, uframe + qh->gap_uf + 1,
qh->period, qh->c_usecs))
goto done;
if (!check_period (ehci, frame, uframe + qh->gap_uf,
qh->period, qh->c_usecs))
goto done;
retval = 0;
}
#endif
done:
return retval;
}
/* "first fit" scheduling policy used the first time through,
* or when the previous schedule slot can't be re-used.
*/
static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
int status;
unsigned uframe;
__hc32 c_mask;
unsigned frame; /* 0..(qh->period - 1), or NO_FRAME */
struct ehci_qh_hw *hw = qh->hw;
qh_refresh(ehci, qh);
hw->hw_next = EHCI_LIST_END(ehci);
frame = qh->start;
/* reuse the previous schedule slots, if we can */
if (frame < qh->period) {
uframe = ffs(hc32_to_cpup(ehci, &hw->hw_info2) & QH_SMASK);
status = check_intr_schedule (ehci, frame, --uframe,
qh, &c_mask);
} else {
uframe = 0;
c_mask = 0;
status = -ENOSPC;
}
/* else scan the schedule to find a group of slots such that all
* uframes have enough periodic bandwidth available.
*/
if (status) {
/* "normal" case, uframing flexible except with splits */
if (qh->period) {
int i;
for (i = qh->period; status && i > 0; --i) {
frame = ++ehci->random_frame % qh->period;
for (uframe = 0; uframe < 8; uframe++) {
status = check_intr_schedule (ehci,
frame, uframe, qh,
&c_mask);
if (status == 0)
break;
}
}
/* qh->period == 0 means every uframe */
} else {
frame = 0;
status = check_intr_schedule (ehci, 0, 0, qh, &c_mask);
}
if (status)
goto done;
qh->start = frame;
/* reset S-frame and (maybe) C-frame masks */
hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
hw->hw_info2 |= qh->period
? cpu_to_hc32(ehci, 1 << uframe)
: cpu_to_hc32(ehci, QH_SMASK);
hw->hw_info2 |= c_mask;
} else
ehci_dbg (ehci, "reused qh %p schedule\n", qh);
/* stuff into the periodic schedule */
status = qh_link_periodic (ehci, qh);
done:
return status;
}
static int intr_submit (
struct ehci_hcd *ehci,
struct urb *urb,
struct list_head *qtd_list,
gfp_t mem_flags
) {
unsigned epnum;
unsigned long flags;
struct ehci_qh *qh;
int status;
struct list_head empty;
/* get endpoint and transfer/schedule data */
epnum = urb->ep->desc.bEndpointAddress;
spin_lock_irqsave (&ehci->lock, flags);
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
&ehci_to_hcd(ehci)->flags))) {
status = -ESHUTDOWN;
goto done_not_linked;
}
status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
if (unlikely(status))
goto done_not_linked;
/* get qh and force any scheduling errors */
INIT_LIST_HEAD (&empty);
qh = qh_append_tds(ehci, urb, &empty, epnum, &urb->ep->hcpriv);
if (qh == NULL) {
status = -ENOMEM;
goto done;
}
if (qh->qh_state == QH_STATE_IDLE) {
if ((status = qh_schedule (ehci, qh)) != 0)
goto done;
}
/* then queue the urb's tds to the qh */
qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
BUG_ON (qh == NULL);
/* ... update usbfs periodic stats */
ehci_to_hcd(ehci)->self.bandwidth_int_reqs++;
done:
if (unlikely(status))
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
done_not_linked:
spin_unlock_irqrestore (&ehci->lock, flags);
if (status)
qtd_list_free (ehci, urb, qtd_list);
return status;
}
/*-------------------------------------------------------------------------*/
/* ehci_iso_stream ops work with both ITD and SITD */
static struct ehci_iso_stream *
iso_stream_alloc (gfp_t mem_flags)
{
struct ehci_iso_stream *stream;
stream = kzalloc(sizeof *stream, mem_flags);
if (likely (stream != NULL)) {
INIT_LIST_HEAD(&stream->td_list);
INIT_LIST_HEAD(&stream->free_list);
stream->next_uframe = -1;
stream->refcount = 1;
}
return stream;
}
static void
iso_stream_init (
struct ehci_hcd *ehci,
struct ehci_iso_stream *stream,
struct usb_device *dev,
int pipe,
unsigned interval
)
{
static const u8 smask_out [] = { 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f };
u32 buf1;
unsigned epnum, maxp;
int is_input;
long bandwidth;
/*
* this might be a "high bandwidth" highspeed endpoint,
* as encoded in the ep descriptor's wMaxPacket field
*/
epnum = usb_pipeendpoint (pipe);
is_input = usb_pipein (pipe) ? USB_DIR_IN : 0;
maxp = usb_maxpacket(dev, pipe, !is_input);
if (is_input) {
buf1 = (1 << 11);
} else {
buf1 = 0;
}
/* knows about ITD vs SITD */
if (dev->speed == USB_SPEED_HIGH) {
unsigned multi = hb_mult(maxp);
stream->highspeed = 1;
maxp = max_packet(maxp);
buf1 |= maxp;
maxp *= multi;
stream->buf0 = cpu_to_hc32(ehci, (epnum << 8) | dev->devnum);
stream->buf1 = cpu_to_hc32(ehci, buf1);
stream->buf2 = cpu_to_hc32(ehci, multi);
/* usbfs wants to report the average usecs per frame tied up
* when transfers on this endpoint are scheduled ...
*/
stream->usecs = HS_USECS_ISO (maxp);
bandwidth = stream->usecs * 8;
bandwidth /= interval;
} else {
u32 addr;
int think_time;
int hs_transfers;
addr = dev->ttport << 24;
if (!ehci_is_TDI(ehci)
|| (dev->tt->hub !=
ehci_to_hcd(ehci)->self.root_hub))
addr |= dev->tt->hub->devnum << 16;
addr |= epnum << 8;
addr |= dev->devnum;
stream->usecs = HS_USECS_ISO (maxp);
think_time = dev->tt ? dev->tt->think_time : 0;
stream->tt_usecs = NS_TO_US (think_time + usb_calc_bus_time (
dev->speed, is_input, 1, maxp));
hs_transfers = max (1u, (maxp + 187) / 188);
if (is_input) {
u32 tmp;
addr |= 1 << 31;
stream->c_usecs = stream->usecs;
stream->usecs = HS_USECS_ISO (1);
stream->raw_mask = 1;
/* c-mask as specified in USB 2.0 11.18.4 3.c */
tmp = (1 << (hs_transfers + 2)) - 1;
stream->raw_mask |= tmp << (8 + 2);
} else
stream->raw_mask = smask_out [hs_transfers - 1];
bandwidth = stream->usecs + stream->c_usecs;
bandwidth /= interval << 3;
/* stream->splits gets created from raw_mask later */
stream->address = cpu_to_hc32(ehci, addr);
}
stream->bandwidth = bandwidth;
stream->udev = dev;
stream->bEndpointAddress = is_input | epnum;
stream->interval = interval;
stream->maxp = maxp;
}
static void
iso_stream_put(struct ehci_hcd *ehci, struct ehci_iso_stream *stream)
{
stream->refcount--;
/* free whenever just a dev->ep reference remains.
* not like a QH -- no persistent state (toggle, halt)
*/
if (stream->refcount == 1) {
int is_in;
// BUG_ON (!list_empty(&stream->td_list));
while (!list_empty (&stream->free_list)) {
struct list_head *entry;
entry = stream->free_list.next;
list_del (entry);
/* knows about ITD vs SITD */
if (stream->highspeed) {
struct ehci_itd *itd;
itd = list_entry (entry, struct ehci_itd,
itd_list);
dma_pool_free (ehci->itd_pool, itd,
itd->itd_dma);
} else {
struct ehci_sitd *sitd;
sitd = list_entry (entry, struct ehci_sitd,
sitd_list);
dma_pool_free (ehci->sitd_pool, sitd,
sitd->sitd_dma);
}
}
is_in = (stream->bEndpointAddress & USB_DIR_IN) ? 0x10 : 0;
stream->bEndpointAddress &= 0x0f;
if (stream->ep)
stream->ep->hcpriv = NULL;
if (stream->rescheduled) {
ehci_info (ehci, "ep%d%s-iso rescheduled "
"%lu times in %lu seconds\n",
stream->bEndpointAddress, is_in ? "in" : "out",
stream->rescheduled,
((jiffies - stream->start)/HZ)
);
}
kfree(stream);
}
}
static inline struct ehci_iso_stream *
iso_stream_get (struct ehci_iso_stream *stream)
{
if (likely (stream != NULL))
stream->refcount++;
return stream;
}
static struct ehci_iso_stream *
iso_stream_find (struct ehci_hcd *ehci, struct urb *urb)
{
unsigned epnum;
struct ehci_iso_stream *stream;
struct usb_host_endpoint *ep;
unsigned long flags;
epnum = usb_pipeendpoint (urb->pipe);
if (usb_pipein(urb->pipe))
ep = urb->dev->ep_in[epnum];
else
ep = urb->dev->ep_out[epnum];
spin_lock_irqsave (&ehci->lock, flags);
stream = ep->hcpriv;
if (unlikely (stream == NULL)) {
stream = iso_stream_alloc(GFP_ATOMIC);
if (likely (stream != NULL)) {
/* dev->ep owns the initial refcount */
ep->hcpriv = stream;
stream->ep = ep;
iso_stream_init(ehci, stream, urb->dev, urb->pipe,
urb->interval);
}
/* if dev->ep [epnum] is a QH, info1.maxpacket is nonzero */
} else if (unlikely (stream->hw_info1 != 0)) {
ehci_dbg (ehci, "dev %s ep%d%s, not iso??\n",
urb->dev->devpath, epnum,
usb_pipein(urb->pipe) ? "in" : "out");
stream = NULL;
}
/* caller guarantees an eventual matching iso_stream_put */
stream = iso_stream_get (stream);
spin_unlock_irqrestore (&ehci->lock, flags);
return stream;
}
/*-------------------------------------------------------------------------*/
/* ehci_iso_sched ops can be ITD-only or SITD-only */
static struct ehci_iso_sched *
iso_sched_alloc (unsigned packets, gfp_t mem_flags)
{
struct ehci_iso_sched *iso_sched;
int size = sizeof *iso_sched;
size += packets * sizeof (struct ehci_iso_packet);
iso_sched = kzalloc(size, mem_flags);
if (likely (iso_sched != NULL)) {
INIT_LIST_HEAD (&iso_sched->td_list);
}
return iso_sched;
}
static inline void
itd_sched_init(
struct ehci_hcd *ehci,
struct ehci_iso_sched *iso_sched,
struct ehci_iso_stream *stream,
struct urb *urb
)
{
unsigned i;
dma_addr_t dma = urb->transfer_dma;
/* how many uframes are needed for these transfers */
iso_sched->span = urb->number_of_packets * stream->interval;
/* figure out per-uframe itd fields that we'll need later
* when we fit new itds into the schedule.
*/
for (i = 0; i < urb->number_of_packets; i++) {
struct ehci_iso_packet *uframe = &iso_sched->packet [i];
unsigned length;
dma_addr_t buf;
u32 trans;
length = urb->iso_frame_desc [i].length;
buf = dma + urb->iso_frame_desc [i].offset;
trans = EHCI_ISOC_ACTIVE;
trans |= buf & 0x0fff;
if (unlikely (((i + 1) == urb->number_of_packets))
&& !(urb->transfer_flags & URB_NO_INTERRUPT))
trans |= EHCI_ITD_IOC;
trans |= length << 16;
uframe->transaction = cpu_to_hc32(ehci, trans);
/* might need to cross a buffer page within a uframe */
uframe->bufp = (buf & ~(u64)0x0fff);
buf += length;
if (unlikely ((uframe->bufp != (buf & ~(u64)0x0fff))))
uframe->cross = 1;
}
}
static void
iso_sched_free (
struct ehci_iso_stream *stream,
struct ehci_iso_sched *iso_sched
)
{
if (!iso_sched)
return;
// caller must hold ehci->lock!
list_splice (&iso_sched->td_list, &stream->free_list);
kfree (iso_sched);
}
static int
itd_urb_transaction (
struct ehci_iso_stream *stream,
struct ehci_hcd *ehci,
struct urb *urb,
gfp_t mem_flags
)
{
struct ehci_itd *itd;
dma_addr_t itd_dma;
int i;
unsigned num_itds;
struct ehci_iso_sched *sched;
unsigned long flags;
sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
if (unlikely (sched == NULL))
return -ENOMEM;
itd_sched_init(ehci, sched, stream, urb);
if (urb->interval < 8)
num_itds = 1 + (sched->span + 7) / 8;
else
num_itds = urb->number_of_packets;
/* allocate/init ITDs */
spin_lock_irqsave (&ehci->lock, flags);
for (i = 0; i < num_itds; i++) {
/* free_list.next might be cache-hot ... but maybe
* the HC caches it too. avoid that issue for now.
*/
/* prefer previously-allocated itds */
if (likely (!list_empty(&stream->free_list))) {
itd = list_entry (stream->free_list.prev,
struct ehci_itd, itd_list);
list_del (&itd->itd_list);
itd_dma = itd->itd_dma;
} else {
spin_unlock_irqrestore (&ehci->lock, flags);
itd = dma_pool_alloc (ehci->itd_pool, mem_flags,
&itd_dma);
spin_lock_irqsave (&ehci->lock, flags);
if (!itd) {
iso_sched_free(stream, sched);
spin_unlock_irqrestore(&ehci->lock, flags);
return -ENOMEM;
}
}
memset (itd, 0, sizeof *itd);
itd->itd_dma = itd_dma;
list_add (&itd->itd_list, &sched->td_list);
}
spin_unlock_irqrestore (&ehci->lock, flags);
/* temporarily store schedule info in hcpriv */
urb->hcpriv = sched;
urb->error_count = 0;
return 0;
}
/*-------------------------------------------------------------------------*/
static inline int
itd_slot_ok (
struct ehci_hcd *ehci,
u32 mod,
u32 uframe,
u8 usecs,
u32 period
)
{
uframe %= period;
do {
/* can't commit more than 80% periodic == 100 usec */
if (periodic_usecs (ehci, uframe >> 3, uframe & 0x7)
> (100 - usecs))
return 0;
/* we know urb->interval is 2^N uframes */
uframe += period;
} while (uframe < mod);
return 1;
}
static inline int
sitd_slot_ok (
struct ehci_hcd *ehci,
u32 mod,
struct ehci_iso_stream *stream,
u32 uframe,
struct ehci_iso_sched *sched,
u32 period_uframes
)
{
u32 mask, tmp;
u32 frame, uf;
mask = stream->raw_mask << (uframe & 7);
/* for IN, don't wrap CSPLIT into the next frame */
if (mask & ~0xffff)
return 0;
/* this multi-pass logic is simple, but performance may
* suffer when the schedule data isn't cached.
*/
/* check bandwidth */
uframe %= period_uframes;
do {
u32 max_used;
frame = uframe >> 3;
uf = uframe & 7;
#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
/* The tt's fullspeed bus bandwidth must be available.
* tt_available scheduling guarantees 10+% for control/bulk.
*/
if (!tt_available (ehci, period_uframes << 3,
stream->udev, frame, uf, stream->tt_usecs))
return 0;
#else
/* tt must be idle for start(s), any gap, and csplit.
* assume scheduling slop leaves 10+% for control/bulk.
*/
if (!tt_no_collision (ehci, period_uframes << 3,
stream->udev, frame, mask))
return 0;
#endif
/* check starts (OUT uses more than one) */
max_used = 100 - stream->usecs;
for (tmp = stream->raw_mask & 0xff; tmp; tmp >>= 1, uf++) {
if (periodic_usecs (ehci, frame, uf) > max_used)
return 0;
}
/* for IN, check CSPLIT */
if (stream->c_usecs) {
uf = uframe & 7;
max_used = 100 - stream->c_usecs;
do {
tmp = 1 << uf;
tmp <<= 8;
if ((stream->raw_mask & tmp) == 0)
continue;
if (periodic_usecs (ehci, frame, uf)
> max_used)
return 0;
} while (++uf < 8);
}
/* we know urb->interval is 2^N uframes */
uframe += period_uframes;
} while (uframe < mod);
stream->splits = cpu_to_hc32(ehci, stream->raw_mask << (uframe & 7));
return 1;
}
/*
* This scheduler plans almost as far into the future as it has actual
* periodic schedule slots. (Affected by TUNE_FLS, which defaults to
* "as small as possible" to be cache-friendlier.) That limits the size
* transfers you can stream reliably; avoid more than 64 msec per urb.
* Also avoid queue depths of less than ehci's worst irq latency (affected
* by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
* and other factors); or more than about 230 msec total (for portability,
* given EHCI_TUNE_FLS and the slop). Or, write a smarter scheduler!
*/
#define SCHEDULE_SLOP 80 /* microframes */
static int
iso_stream_schedule (
struct ehci_hcd *ehci,
struct urb *urb,
struct ehci_iso_stream *stream
)
{
u32 now, next, start, period;
int status;
unsigned mod = ehci->periodic_size << 3;
struct ehci_iso_sched *sched = urb->hcpriv;
struct pci_dev *pdev;
if (sched->span > (mod - SCHEDULE_SLOP)) {
ehci_dbg (ehci, "iso request %p too long\n", urb);
status = -EFBIG;
goto fail;
}
if ((stream->depth + sched->span) > mod) {
ehci_dbg (ehci, "request %p would overflow (%d+%d>%d)\n",
urb, stream->depth, sched->span, mod);
status = -EFBIG;
goto fail;
}
period = urb->interval;
if (!stream->highspeed)
period <<= 3;
now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
/* Typical case: reuse current schedule, stream is still active.
* Hopefully there are no gaps from the host falling behind
* (irq delays etc), but if there are we'll take the next
* slot in the schedule, implicitly assuming URB_ISO_ASAP.
*/
if (likely (!list_empty (&stream->td_list))) {
pdev = to_pci_dev(ehci_to_hcd(ehci)->self.controller);
start = stream->next_uframe;
/* For high speed devices, allow scheduling within the
* isochronous scheduling threshold. For full speed devices,
* don't. (Work around for Intel ICH9 bug.)
*/
if (!stream->highspeed &&
pdev->vendor == PCI_VENDOR_ID_INTEL)
next = now + ehci->i_thresh;
else
next = now;
/* Fell behind (by up to twice the slop amount)? */
if (((start - next) & (mod - 1)) >=
mod - 2 * SCHEDULE_SLOP)
start += period * DIV_ROUND_UP(
(next - start) & (mod - 1),
period);
/* Tried to schedule too far into the future? */
if (unlikely(((start - now) & (mod - 1)) + sched->span
>= mod - 2 * SCHEDULE_SLOP)) {
status = -EFBIG;
goto fail;
}
stream->next_uframe = start;
goto ready;
}
/* need to schedule; when's the next (u)frame we could start?
* this is bigger than ehci->i_thresh allows; scheduling itself
* isn't free, the slop should handle reasonably slow cpus. it
* can also help high bandwidth if the dma and irq loads don't
* jump until after the queue is primed.
*/
start = SCHEDULE_SLOP + (now & ~0x07);
start %= mod;
stream->next_uframe = start;
/* NOTE: assumes URB_ISO_ASAP, to limit complexity/bugs */
/* find a uframe slot with enough bandwidth */
for (; start < (stream->next_uframe + period); start++) {
int enough_space;
/* check schedule: enough space? */
if (stream->highspeed)
enough_space = itd_slot_ok (ehci, mod, start,
stream->usecs, period);
else {
if ((start % 8) >= 6)
continue;
enough_space = sitd_slot_ok (ehci, mod, stream,
start, sched, period);
}
/* schedule it here if there's enough bandwidth */
if (enough_space) {
stream->next_uframe = start % mod;
goto ready;
}
}
/* no room in the schedule */
ehci_dbg (ehci, "iso %ssched full %p (now %d max %d)\n",
list_empty (&stream->td_list) ? "" : "re",
urb, now, now + mod);
status = -ENOSPC;
fail:
iso_sched_free (stream, sched);
urb->hcpriv = NULL;
return status;
ready:
/* report high speed start in uframes; full speed, in frames */
urb->start_frame = stream->next_uframe;
if (!stream->highspeed)
urb->start_frame >>= 3;
return 0;
}
/*-------------------------------------------------------------------------*/
static inline void
itd_init(struct ehci_hcd *ehci, struct ehci_iso_stream *stream,
struct ehci_itd *itd)
{
int i;
/* it's been recently zeroed */
itd->hw_next = EHCI_LIST_END(ehci);
itd->hw_bufp [0] = stream->buf0;
itd->hw_bufp [1] = stream->buf1;
itd->hw_bufp [2] = stream->buf2;
for (i = 0; i < 8; i++)
itd->index[i] = -1;
/* All other fields are filled when scheduling */
}
static inline void
itd_patch(
struct ehci_hcd *ehci,
struct ehci_itd *itd,
struct ehci_iso_sched *iso_sched,
unsigned index,
u16 uframe
)
{
struct ehci_iso_packet *uf = &iso_sched->packet [index];
unsigned pg = itd->pg;
// BUG_ON (pg == 6 && uf->cross);
uframe &= 0x07;
itd->index [uframe] = index;
itd->hw_transaction[uframe] = uf->transaction;
itd->hw_transaction[uframe] |= cpu_to_hc32(ehci, pg << 12);
itd->hw_bufp[pg] |= cpu_to_hc32(ehci, uf->bufp & ~(u32)0);
itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(uf->bufp >> 32));
/* iso_frame_desc[].offset must be strictly increasing */
if (unlikely (uf->cross)) {
u64 bufp = uf->bufp + 4096;
itd->pg = ++pg;
itd->hw_bufp[pg] |= cpu_to_hc32(ehci, bufp & ~(u32)0);
itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(bufp >> 32));
}
}
static inline void
itd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_itd *itd)
{
/* always prepend ITD/SITD ... only QH tree is order-sensitive */
itd->itd_next = ehci->pshadow [frame];
itd->hw_next = ehci->periodic [frame];
ehci->pshadow [frame].itd = itd;
itd->frame = frame;
wmb ();
ehci->periodic[frame] = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD);
}
/* fit urb's itds into the selected schedule slot; activate as needed */
static int
itd_link_urb (
struct ehci_hcd *ehci,
struct urb *urb,
unsigned mod,
struct ehci_iso_stream *stream
)
{
int packet;
unsigned next_uframe, uframe, frame;
struct ehci_iso_sched *iso_sched = urb->hcpriv;
struct ehci_itd *itd;
next_uframe = stream->next_uframe % mod;
if (unlikely (list_empty(&stream->td_list))) {
ehci_to_hcd(ehci)->self.bandwidth_allocated
+= stream->bandwidth;
ehci_vdbg (ehci,
"schedule devp %s ep%d%s-iso period %d start %d.%d\n",
urb->dev->devpath, stream->bEndpointAddress & 0x0f,
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
urb->interval,
next_uframe >> 3, next_uframe & 0x7);
stream->start = jiffies;
}
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
/* fill iTDs uframe by uframe */
for (packet = 0, itd = NULL; packet < urb->number_of_packets; ) {
if (itd == NULL) {
/* ASSERT: we have all necessary itds */
// BUG_ON (list_empty (&iso_sched->td_list));
/* ASSERT: no itds for this endpoint in this uframe */
itd = list_entry (iso_sched->td_list.next,
struct ehci_itd, itd_list);
list_move_tail (&itd->itd_list, &stream->td_list);
itd->stream = iso_stream_get (stream);
itd->urb = urb;
itd_init (ehci, stream, itd);
}
uframe = next_uframe & 0x07;
frame = next_uframe >> 3;
itd_patch(ehci, itd, iso_sched, packet, uframe);
next_uframe += stream->interval;
stream->depth += stream->interval;
next_uframe %= mod;
packet++;
/* link completed itds into the schedule */
if (((next_uframe >> 3) != frame)
|| packet == urb->number_of_packets) {
itd_link (ehci, frame % ehci->periodic_size, itd);
itd = NULL;
}
}
stream->next_uframe = next_uframe;
/* don't need that schedule data any more */
iso_sched_free (stream, iso_sched);
urb->hcpriv = NULL;
timer_action (ehci, TIMER_IO_WATCHDOG);
return enable_periodic(ehci);
}
#define ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
/* Process and recycle a completed ITD. Return true iff its urb completed,
* and hence its completion callback probably added things to the hardware
* schedule.
*
* Note that we carefully avoid recycling this descriptor until after any
* completion callback runs, so that it won't be reused quickly. That is,
* assuming (a) no more than two urbs per frame on this endpoint, and also
* (b) only this endpoint's completions submit URBs. It seems some silicon
* corrupts things if you reuse completed descriptors very quickly...
*/
static unsigned
itd_complete (
struct ehci_hcd *ehci,
struct ehci_itd *itd
) {
struct urb *urb = itd->urb;
struct usb_iso_packet_descriptor *desc;
u32 t;
unsigned uframe;
int urb_index = -1;
struct ehci_iso_stream *stream = itd->stream;
struct usb_device *dev;
unsigned retval = false;
/* for each uframe with a packet */
for (uframe = 0; uframe < 8; uframe++) {
if (likely (itd->index[uframe] == -1))
continue;
urb_index = itd->index[uframe];
desc = &urb->iso_frame_desc [urb_index];
t = hc32_to_cpup(ehci, &itd->hw_transaction [uframe]);
itd->hw_transaction [uframe] = 0;
stream->depth -= stream->interval;
/* report transfer status */
if (unlikely (t & ISO_ERRS)) {
urb->error_count++;
if (t & EHCI_ISOC_BUF_ERR)
desc->status = usb_pipein (urb->pipe)
? -ENOSR /* hc couldn't read */
: -ECOMM; /* hc couldn't write */
else if (t & EHCI_ISOC_BABBLE)
desc->status = -EOVERFLOW;
else /* (t & EHCI_ISOC_XACTERR) */
desc->status = -EPROTO;
/* HC need not update length with this error */
if (!(t & EHCI_ISOC_BABBLE)) {
desc->actual_length = EHCI_ITD_LENGTH(t);
urb->actual_length += desc->actual_length;
}
} else if (likely ((t & EHCI_ISOC_ACTIVE) == 0)) {
desc->status = 0;
desc->actual_length = EHCI_ITD_LENGTH(t);
urb->actual_length += desc->actual_length;
} else {
/* URB was too late */
desc->status = -EXDEV;
}
}
/* handle completion now? */
if (likely ((urb_index + 1) != urb->number_of_packets))
goto done;
/* ASSERT: it's really the last itd for this urb
list_for_each_entry (itd, &stream->td_list, itd_list)
BUG_ON (itd->urb == urb);
*/
/* give urb back to the driver; completion often (re)submits */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
retval = true;
urb = NULL;
(void) disable_periodic(ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (unlikely(list_is_singular(&stream->td_list))) {
ehci_to_hcd(ehci)->self.bandwidth_allocated
-= stream->bandwidth;
ehci_vdbg (ehci,
"deschedule devp %s ep%d%s-iso\n",
dev->devpath, stream->bEndpointAddress & 0x0f,
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
}
iso_stream_put (ehci, stream);
done:
itd->urb = NULL;
if (ehci->clock_frame != itd->frame || itd->index[7] != -1) {
/* OK to recycle this ITD now. */
itd->stream = NULL;
list_move(&itd->itd_list, &stream->free_list);
iso_stream_put(ehci, stream);
} else {
/* HW might remember this ITD, so we can't recycle it yet.
* Move it to a safe place until a new frame starts.
*/
list_move(&itd->itd_list, &ehci->cached_itd_list);
if (stream->refcount == 2) {
/* If iso_stream_put() were called here, stream
* would be freed. Instead, just prevent reuse.
*/
stream->ep->hcpriv = NULL;
stream->ep = NULL;
}
}
return retval;
}
/*-------------------------------------------------------------------------*/
static int itd_submit (struct ehci_hcd *ehci, struct urb *urb,
gfp_t mem_flags)
{
int status = -EINVAL;
unsigned long flags;
struct ehci_iso_stream *stream;
/* Get iso_stream head */
stream = iso_stream_find (ehci, urb);
if (unlikely (stream == NULL)) {
ehci_dbg (ehci, "can't get iso stream\n");
return -ENOMEM;
}
if (unlikely (urb->interval != stream->interval)) {
ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
stream->interval, urb->interval);
goto done;
}
#ifdef EHCI_URB_TRACE
ehci_dbg (ehci,
"%s %s urb %p ep%d%s len %d, %d pkts %d uframes [%p]\n",
__func__, urb->dev->devpath, urb,
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out",
urb->transfer_buffer_length,
urb->number_of_packets, urb->interval,
stream);
#endif
/* allocate ITDs w/o locking anything */
status = itd_urb_transaction (stream, ehci, urb, mem_flags);
if (unlikely (status < 0)) {
ehci_dbg (ehci, "can't init itds\n");
goto done;
}
/* schedule ... need to lock */
spin_lock_irqsave (&ehci->lock, flags);
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
&ehci_to_hcd(ehci)->flags))) {
status = -ESHUTDOWN;
goto done_not_linked;
}
status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
if (unlikely(status))
goto done_not_linked;
status = iso_stream_schedule(ehci, urb, stream);
if (likely (status == 0))
itd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
else
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
done_not_linked:
spin_unlock_irqrestore (&ehci->lock, flags);
done:
if (unlikely (status < 0))
iso_stream_put (ehci, stream);
return status;
}
/*-------------------------------------------------------------------------*/
/*
* "Split ISO TDs" ... used for USB 1.1 devices going through the
* TTs in USB 2.0 hubs. These need microframe scheduling.
*/
static inline void
sitd_sched_init(
struct ehci_hcd *ehci,
struct ehci_iso_sched *iso_sched,
struct ehci_iso_stream *stream,
struct urb *urb
)
{
unsigned i;
dma_addr_t dma = urb->transfer_dma;
/* how many frames are needed for these transfers */
iso_sched->span = urb->number_of_packets * stream->interval;
/* figure out per-frame sitd fields that we'll need later
* when we fit new sitds into the schedule.
*/
for (i = 0; i < urb->number_of_packets; i++) {
struct ehci_iso_packet *packet = &iso_sched->packet [i];
unsigned length;
dma_addr_t buf;
u32 trans;
length = urb->iso_frame_desc [i].length & 0x03ff;
buf = dma + urb->iso_frame_desc [i].offset;
trans = SITD_STS_ACTIVE;
if (((i + 1) == urb->number_of_packets)
&& !(urb->transfer_flags & URB_NO_INTERRUPT))
trans |= SITD_IOC;
trans |= length << 16;
packet->transaction = cpu_to_hc32(ehci, trans);
/* might need to cross a buffer page within a td */
packet->bufp = buf;
packet->buf1 = (buf + length) & ~0x0fff;
if (packet->buf1 != (buf & ~(u64)0x0fff))
packet->cross = 1;
/* OUT uses multiple start-splits */
if (stream->bEndpointAddress & USB_DIR_IN)
continue;
length = (length + 187) / 188;
if (length > 1) /* BEGIN vs ALL */
length |= 1 << 3;
packet->buf1 |= length;
}
}
static int
sitd_urb_transaction (
struct ehci_iso_stream *stream,
struct ehci_hcd *ehci,
struct urb *urb,
gfp_t mem_flags
)
{
struct ehci_sitd *sitd;
dma_addr_t sitd_dma;
int i;
struct ehci_iso_sched *iso_sched;
unsigned long flags;
iso_sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
if (iso_sched == NULL)
return -ENOMEM;
sitd_sched_init(ehci, iso_sched, stream, urb);
/* allocate/init sITDs */
spin_lock_irqsave (&ehci->lock, flags);
for (i = 0; i < urb->number_of_packets; i++) {
/* NOTE: for now, we don't try to handle wraparound cases
* for IN (using sitd->hw_backpointer, like a FSTN), which
* means we never need two sitds for full speed packets.
*/
/* free_list.next might be cache-hot ... but maybe
* the HC caches it too. avoid that issue for now.
*/
/* prefer previously-allocated sitds */
if (!list_empty(&stream->free_list)) {
sitd = list_entry (stream->free_list.prev,
struct ehci_sitd, sitd_list);
list_del (&sitd->sitd_list);
sitd_dma = sitd->sitd_dma;
} else {
spin_unlock_irqrestore (&ehci->lock, flags);
sitd = dma_pool_alloc (ehci->sitd_pool, mem_flags,
&sitd_dma);
spin_lock_irqsave (&ehci->lock, flags);
if (!sitd) {
iso_sched_free(stream, iso_sched);
spin_unlock_irqrestore(&ehci->lock, flags);
return -ENOMEM;
}
}
memset (sitd, 0, sizeof *sitd);
sitd->sitd_dma = sitd_dma;
list_add (&sitd->sitd_list, &iso_sched->td_list);
}
/* temporarily store schedule info in hcpriv */
urb->hcpriv = iso_sched;
urb->error_count = 0;
spin_unlock_irqrestore (&ehci->lock, flags);
return 0;
}
/*-------------------------------------------------------------------------*/
static inline void
sitd_patch(
struct ehci_hcd *ehci,
struct ehci_iso_stream *stream,
struct ehci_sitd *sitd,
struct ehci_iso_sched *iso_sched,
unsigned index
)
{
struct ehci_iso_packet *uf = &iso_sched->packet [index];
u64 bufp = uf->bufp;
sitd->hw_next = EHCI_LIST_END(ehci);
sitd->hw_fullspeed_ep = stream->address;
sitd->hw_uframe = stream->splits;
sitd->hw_results = uf->transaction;
sitd->hw_backpointer = EHCI_LIST_END(ehci);
bufp = uf->bufp;
sitd->hw_buf[0] = cpu_to_hc32(ehci, bufp);
sitd->hw_buf_hi[0] = cpu_to_hc32(ehci, bufp >> 32);
sitd->hw_buf[1] = cpu_to_hc32(ehci, uf->buf1);
if (uf->cross)
bufp += 4096;
sitd->hw_buf_hi[1] = cpu_to_hc32(ehci, bufp >> 32);
sitd->index = index;
}
static inline void
sitd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_sitd *sitd)
{
/* note: sitd ordering could matter (CSPLIT then SSPLIT) */
sitd->sitd_next = ehci->pshadow [frame];
sitd->hw_next = ehci->periodic [frame];
ehci->pshadow [frame].sitd = sitd;
sitd->frame = frame;
wmb ();
ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD);
}
/* fit urb's sitds into the selected schedule slot; activate as needed */
static int
sitd_link_urb (
struct ehci_hcd *ehci,
struct urb *urb,
unsigned mod,
struct ehci_iso_stream *stream
)
{
int packet;
unsigned next_uframe;
struct ehci_iso_sched *sched = urb->hcpriv;
struct ehci_sitd *sitd;
next_uframe = stream->next_uframe;
if (list_empty(&stream->td_list)) {
/* usbfs ignores TT bandwidth */
ehci_to_hcd(ehci)->self.bandwidth_allocated
+= stream->bandwidth;
ehci_vdbg (ehci,
"sched devp %s ep%d%s-iso [%d] %dms/%04x\n",
urb->dev->devpath, stream->bEndpointAddress & 0x0f,
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
(next_uframe >> 3) % ehci->periodic_size,
stream->interval, hc32_to_cpu(ehci, stream->splits));
stream->start = jiffies;
}
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
/* fill sITDs frame by frame */
for (packet = 0, sitd = NULL;
packet < urb->number_of_packets;
packet++) {
/* ASSERT: we have all necessary sitds */
BUG_ON (list_empty (&sched->td_list));
/* ASSERT: no itds for this endpoint in this frame */
sitd = list_entry (sched->td_list.next,
struct ehci_sitd, sitd_list);
list_move_tail (&sitd->sitd_list, &stream->td_list);
sitd->stream = iso_stream_get (stream);
sitd->urb = urb;
sitd_patch(ehci, stream, sitd, sched, packet);
sitd_link (ehci, (next_uframe >> 3) % ehci->periodic_size,
sitd);
next_uframe += stream->interval << 3;
stream->depth += stream->interval << 3;
}
stream->next_uframe = next_uframe % mod;
/* don't need that schedule data any more */
iso_sched_free (stream, sched);
urb->hcpriv = NULL;
timer_action (ehci, TIMER_IO_WATCHDOG);
return enable_periodic(ehci);
}
/*-------------------------------------------------------------------------*/
#define SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
| SITD_STS_XACT | SITD_STS_MMF)
/* Process and recycle a completed SITD. Return true iff its urb completed,
* and hence its completion callback probably added things to the hardware
* schedule.
*
* Note that we carefully avoid recycling this descriptor until after any
* completion callback runs, so that it won't be reused quickly. That is,
* assuming (a) no more than two urbs per frame on this endpoint, and also
* (b) only this endpoint's completions submit URBs. It seems some silicon
* corrupts things if you reuse completed descriptors very quickly...
*/
static unsigned
sitd_complete (
struct ehci_hcd *ehci,
struct ehci_sitd *sitd
) {
struct urb *urb = sitd->urb;
struct usb_iso_packet_descriptor *desc;
u32 t;
int urb_index = -1;
struct ehci_iso_stream *stream = sitd->stream;
struct usb_device *dev;
unsigned retval = false;
urb_index = sitd->index;
desc = &urb->iso_frame_desc [urb_index];
t = hc32_to_cpup(ehci, &sitd->hw_results);
/* report transfer status */
if (t & SITD_ERRS) {
urb->error_count++;
if (t & SITD_STS_DBE)
desc->status = usb_pipein (urb->pipe)
? -ENOSR /* hc couldn't read */
: -ECOMM; /* hc couldn't write */
else if (t & SITD_STS_BABBLE)
desc->status = -EOVERFLOW;
else /* XACT, MMF, etc */
desc->status = -EPROTO;
} else {
desc->status = 0;
desc->actual_length = desc->length - SITD_LENGTH(t);
urb->actual_length += desc->actual_length;
}
stream->depth -= stream->interval << 3;
/* handle completion now? */
if ((urb_index + 1) != urb->number_of_packets)
goto done;
/* ASSERT: it's really the last sitd for this urb
list_for_each_entry (sitd, &stream->td_list, sitd_list)
BUG_ON (sitd->urb == urb);
*/
/* give urb back to the driver; completion often (re)submits */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
retval = true;
urb = NULL;
(void) disable_periodic(ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (list_is_singular(&stream->td_list)) {
ehci_to_hcd(ehci)->self.bandwidth_allocated
-= stream->bandwidth;
ehci_vdbg (ehci,
"deschedule devp %s ep%d%s-iso\n",
dev->devpath, stream->bEndpointAddress & 0x0f,
(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
}
iso_stream_put (ehci, stream);
/* OK to recycle this SITD now that its completion callback ran. */
done:
sitd->urb = NULL;
sitd->stream = NULL;
list_move(&sitd->sitd_list, &stream->free_list);
iso_stream_put(ehci, stream);
return retval;
}
static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
gfp_t mem_flags)
{
int status = -EINVAL;
unsigned long flags;
struct ehci_iso_stream *stream;
/* Get iso_stream head */
stream = iso_stream_find (ehci, urb);
if (stream == NULL) {
ehci_dbg (ehci, "can't get iso stream\n");
return -ENOMEM;
}
if (urb->interval != stream->interval) {
ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
stream->interval, urb->interval);
goto done;
}
#ifdef EHCI_URB_TRACE
ehci_dbg (ehci,
"submit %p dev%s ep%d%s-iso len %d\n",
urb, urb->dev->devpath,
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out",
urb->transfer_buffer_length);
#endif
/* allocate SITDs */
status = sitd_urb_transaction (stream, ehci, urb, mem_flags);
if (status < 0) {
ehci_dbg (ehci, "can't init sitds\n");
goto done;
}
/* schedule ... need to lock */
spin_lock_irqsave (&ehci->lock, flags);
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
&ehci_to_hcd(ehci)->flags))) {
status = -ESHUTDOWN;
goto done_not_linked;
}
status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
if (unlikely(status))
goto done_not_linked;
status = iso_stream_schedule(ehci, urb, stream);
if (status == 0)
sitd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
else
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
done_not_linked:
spin_unlock_irqrestore (&ehci->lock, flags);
done:
if (status < 0)
iso_stream_put (ehci, stream);
return status;
}
/*-------------------------------------------------------------------------*/
static void free_cached_itd_list(struct ehci_hcd *ehci)
{
struct ehci_itd *itd, *n;
list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
struct ehci_iso_stream *stream = itd->stream;
itd->stream = NULL;
list_move(&itd->itd_list, &stream->free_list);
iso_stream_put(ehci, stream);
}
}
/*-------------------------------------------------------------------------*/
static void
scan_periodic (struct ehci_hcd *ehci)
{
unsigned now_uframe, frame, clock, clock_frame, mod;
unsigned modified;
mod = ehci->periodic_size << 3;
/*
* When running, scan from last scan point up to "now"
* else clean up by scanning everything that's left.
* Touches as few pages as possible: cache-friendly.
*/
now_uframe = ehci->next_uframe;
if (HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
clock = ehci_readl(ehci, &ehci->regs->frame_index);
clock_frame = (clock >> 3) % ehci->periodic_size;
} else {
clock = now_uframe + mod - 1;
clock_frame = -1;
}
if (ehci->clock_frame != clock_frame) {
free_cached_itd_list(ehci);
ehci->clock_frame = clock_frame;
}
clock %= mod;
clock_frame = clock >> 3;
for (;;) {
union ehci_shadow q, *q_p;
__hc32 type, *hw_p;
unsigned incomplete = false;
frame = now_uframe >> 3;
restart:
/* scan each element in frame's queue for completions */
q_p = &ehci->pshadow [frame];
hw_p = &ehci->periodic [frame];
q.ptr = q_p->ptr;
type = Q_NEXT_TYPE(ehci, *hw_p);
modified = 0;
while (q.ptr != NULL) {
unsigned uf;
union ehci_shadow temp;
int live;
live = HC_IS_RUNNING (ehci_to_hcd(ehci)->state);
switch (hc32_to_cpu(ehci, type)) {
case Q_TYPE_QH:
/* handle any completions */
temp.qh = qh_get (q.qh);
type = Q_NEXT_TYPE(ehci, q.qh->hw->hw_next);
q = q.qh->qh_next;
modified = qh_completions (ehci, temp.qh);
if (unlikely(list_empty(&temp.qh->qtd_list) ||
temp.qh->needs_rescan))
intr_deschedule (ehci, temp.qh);
qh_put (temp.qh);
break;
case Q_TYPE_FSTN:
/* for "save place" FSTNs, look at QH entries
* in the previous frame for completions.
*/
if (q.fstn->hw_prev != EHCI_LIST_END(ehci)) {
dbg ("ignoring completions from FSTNs");
}
type = Q_NEXT_TYPE(ehci, q.fstn->hw_next);
q = q.fstn->fstn_next;
break;
case Q_TYPE_ITD:
/* If this ITD is still active, leave it for
* later processing ... check the next entry.
* No need to check for activity unless the
* frame is current.
*/
if (frame == clock_frame && live) {
rmb();
for (uf = 0; uf < 8; uf++) {
if (q.itd->hw_transaction[uf] &
ITD_ACTIVE(ehci))
break;
}
if (uf < 8) {
incomplete = true;
q_p = &q.itd->itd_next;
hw_p = &q.itd->hw_next;
type = Q_NEXT_TYPE(ehci,
q.itd->hw_next);
q = *q_p;
break;
}
}
/* Take finished ITDs out of the schedule
* and process them: recycle, maybe report
* URB completion. HC won't cache the
* pointer for much longer, if at all.
*/
*q_p = q.itd->itd_next;
*hw_p = q.itd->hw_next;
type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
wmb();
modified = itd_complete (ehci, q.itd);
q = *q_p;
break;
case Q_TYPE_SITD:
/* If this SITD is still active, leave it for
* later processing ... check the next entry.
* No need to check for activity unless the
* frame is current.
*/
if (frame == clock_frame && live &&
(q.sitd->hw_results &
SITD_ACTIVE(ehci))) {
incomplete = true;
q_p = &q.sitd->sitd_next;
hw_p = &q.sitd->hw_next;
type = Q_NEXT_TYPE(ehci,
q.sitd->hw_next);
q = *q_p;
break;
}
/* Take finished SITDs out of the schedule
* and process them: recycle, maybe report
* URB completion.
*/
*q_p = q.sitd->sitd_next;
*hw_p = q.sitd->hw_next;
type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
wmb();
modified = sitd_complete (ehci, q.sitd);
q = *q_p;
break;
default:
dbg ("corrupt type %d frame %d shadow %p",
type, frame, q.ptr);
// BUG ();
q.ptr = NULL;
}
/* assume completion callbacks modify the queue */
if (unlikely (modified)) {
if (likely(ehci->periodic_sched > 0))
goto restart;
/* short-circuit this scan */
now_uframe = clock;
break;
}
}
/* If we can tell we caught up to the hardware, stop now.
* We can't advance our scan without collecting the ISO
* transfers that are still pending in this frame.
*/
if (incomplete && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
ehci->next_uframe = now_uframe;
break;
}
// FIXME: this assumes we won't get lapped when
// latencies climb; that should be rare, but...
// detect it, and just go all the way around.
// FLR might help detect this case, so long as latencies
// don't exceed periodic_size msec (default 1.024 sec).
// FIXME: likewise assumes HC doesn't halt mid-scan
if (now_uframe == clock) {
unsigned now;
if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
|| ehci->periodic_sched == 0)
break;
ehci->next_uframe = now_uframe;
now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
if (now_uframe == now)
break;
/* rescan the rest of this frame, then ... */
clock = now;
clock_frame = clock >> 3;
if (ehci->clock_frame != clock_frame) {
free_cached_itd_list(ehci);
ehci->clock_frame = clock_frame;
}
} else {
now_uframe++;
now_uframe %= mod;
}
}
}
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