The commit 4547be7 rewrites suspend and resume functions. According
to this rewrite, when a serial port is a printk console device and
can suspend(without set no_console_suspend flag), it will definitely
call set_termios function during its resume, but parameter termios
isn't initialized, this will pass an unpredictable config to the
serial port. If this serial port is not a userspace opened tty device
, a suspend and resume action will make this serial port unusable.
I.E. ttyS0 is a printk console device, ttyS1 or keyboard+display is
userspace tty device, a suspend/resume action will make ttyS0
unusable.
If a serial port is both a printk console device and an opened tty
device, this issue can be overcome because it will call set_termios
again with the correct parameter in the uart_change_speed function.
Refer to the deleted content of commit 4547be7, revert parts relate
to restore settings into parameter termios. It is safe because if
a serial port is a printk console only device, the only meaningful
field in termios is c_cflag and its old config is saved in
uport->cons->cflag, if this port is also an opened tty device,
it will clear uport->cons->cflag in the uart_open and the old config
is saved in tty->termios.
Signed-off-by: Jason Wang <jason77.wang@gmail.com>
Acked-by: Stanislav Brabec <sbrabec@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The commit 4547be7 rewrites suspend and resume functions, this
introduces a problem on the OMAP3EVM platoform. when the kernel boots
with no_console_suspend and we suspend the kernel, then resume it,
the serial console will be not usable. This problem should be common
for all platforms.
The cause for this problem is that when enter suspend, if we choose
no_console_suspend, the console_stop will be skiped. But in resume
function, the console port will be set to uninitialized state by
calling set_termios function and the console_start is called without
checking whether the no_console_suspend is set, Now fix it.
Signed-off-by: Jason Wang <jason77.wang@gmail.com>
Acked-by: Stanislav Brabec <sbrabec@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some wait_until_sent versions require the big
tty mutex, others don't and some callers of
wait_until_sent already hold it while other don't.
That leads to recursive use of the BTM in these
functions, which we're trying to get rid of.
This turns all cleans up the locking there so
that the driver's wait_until_sent function
never takes the BTM itself if it is already
called with that lock held.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As a preparation for replacing the big kernel lock
in the TTY layer, wrap all the callers in new
macros tty_lock, tty_lock_nested and tty_unlock.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move termios initialization in open into uart_dtr_rts to make sure
it always gets called when necessary. Based on a suggestion from
Alan Cox.
Alan writes:
Ok this sort of makes sense. Something isn't getting initialised and both
getty and minicom will do a termios set which is sorting it out.
This is occurring because the generic block_til_ready sets
ASYNCB_NORMAL_ACTIVE so the termios updating gets skipped.
This patch should cure it and then we can think about doing it more
elegantly by getting the serial layer to use tty_port_open, kfifo and
the like and removing the tons of repeated crap in all the drivers.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Tony Luck <tony.luck@intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Our code now rather closely resembles the helper, so switch to it.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The port mutex protects port->tty, but these paths never need to walk from
port->tty. They do need the low level lock as the API expects that but they
already also take it.
Thus we can drop the extra mutex lock calls here.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We can make this the same as the ones that will be needed by the tty_port
helper logic that we want to move to but still call them from the existing
code base.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We want to push the lock/unlock into the helper functions so that we
can prepare to move to using the tty_port helper. The expansion initially
comes out a bit ugly but its worth the temporary expansion IMHO just so
we can produce a nice testable series of changes.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Pass down the ldisc number so that the drivers don't have to peek into the
tty object themselves. This lets us get rid of another case of back referencing
port to tty which we don't want (because of races versus hangup/close).
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make it robust against hang up events. In most cases we can do this simply
by passing the right things in the first place.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In that situation if the old rate is invalid and the new rate is invalid
and the chip cannot do 9600 baud we report zero, which makes all the
drivers explode.
Instead force the rate based on min/max
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Perform a tricky suspend/resume even with no_console_suspend.
With no_console_suspend, kernel skips serial port suspend/resume and the
serial hardware may remain in undefined state after resume. It actually
happens on devices that don't have BIOS that handle serial
initialization. It makes impossible to use serial console after resume.
Devices affected by this problem include:
Sharp Zaurus devices
Several PXA based ARM embedded boards
The patch does:
- Save the hardware state
- Perform buffer flush in time of its suspend call
- Tell the driver that port is suspended
- But still accept new data
- And keep console hardware in state that allows to send them
It allows to capture late console messages without breaking console
after resume.
This is just a resend of a patch discussed in these threads, as the
patch was not yet applied.
"Possible suspend/resume regression in .32-rc?" (Nov 1-5, 2009, ARM
list, later LKML)
"serial-core: resume serial hardware with no_console_suspend" (Sep
15-Oct 18, 2009, LKML & ARM lists)
Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>
Tested-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Tested-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 46d57a449a ("serial: use tty_port pointers in the core code")
contained two bugs that causes (rare) crashes:
- the rename typoed one site
- a NULL check was missed
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix new kernel-doc warnings in serial_core.[hc] files.
Warning(include/linux/serial_core.h:485): No description found for parameter 'uport'
Warning(include/linux/serial_core.h:485): Excess function parameter 'port' description in 'uart_handle_dcd_change'
Warning(include/linux/serial_core.h:511): No description found for parameter 'uport'
Warning(include/linux/serial_core.h:511): Excess function parameter 'port' description in 'uart_handle_cts_change'
Warning(drivers/serial/serial_core.c:2437): No description found for parameter 'uport'
Warning(drivers/serial/serial_core.c:2437): Excess function parameter 'port' description in 'uart_add_one_port'
Warning(drivers/serial/serial_core.c:2509): No description found for parameter 'uport'
Warning(drivers/serial/serial_core.c:2509): Excess function parameter 'port' description in 'uart_remove_one_port'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b5b82df6, from May 2007, breaks no_console_suspend on the OLPC
XO laptop. Basically what happens is that upon returning from resume,
serial8250_resume_port() will reconfigure the port for high speed
mode and all console output will be garbled, making debug of the
resume path painful. This patch modifies uart_resume_port() to
reset the port to the state it was in before we suspended.
Original patch by Marcelo Tosatti
Second patch by Deepak then reworked by Alan to fit with the tty changes
before it got submitted. Also fixed the console path to set c_i/ospeed as
some drivers require the termios fields are valid
Signed-off-by: Deepak Saxena <dsaxena@laptop.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The serial layer for some reason uses different defines for the special
case close delays and then conditionally switches to/from the normal ones
in the ioctls.
Remove this rather pointless abstraction
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This little helper is now tty_port specific and useful generally so move it
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
They cover essentially the same stuff and we can therefore fold it into the
tty_port one.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fortunately the serial layer was designed to use the same flag values but
with different names. It has its own SUSPENDED flag which is a free slot in
the ASYNC flags so we allocate it in the ASYNC flags instead.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Extract out a lot of the x.port. uses and also show up where there are
things left to be isolated that prevent use using the port helpers in the
serial layer at this point
Signed-off-by: Alan Cox <alan@linux.intel.com>
We moved this into uart_state, now move the fields out of the separate
structure and kill it off.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
"struct tty_driver *" lies in m->private not in v which is
SEQ_TOKEN_START which is 1 which is enough to trigger NULL dereference
next line:
BUG: unable to handle kernel NULL pointer dereference at 000000ad
IP: [<c040d689>] uart_proc_show+0xe/0x2b0
Noticed by Linus.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add flag value UPF_FIXED_TYPE which specifies that the UART type is
known and should not be probed. For this case the UARTs properties
are just copied out of the uart_config entry.
This allows us to keep SOC specific 8250 probe code out of 8250.c. In
this case we know the serial hardware will not be changing as it is on
the same silicon as the CPU, and we can specify it with certainty in
the board/cpu setup code.
The alternative is to load up 8250.c with a bunch of OCTEON specific
special cases in the probing code.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the tty_port and uart_info bits around a little. By embedding the uart_info
into the uart_port we get rid of lots of corner case testing and also get the
ability to go port<->state<->info which is a bit more elegant than the current
data structures.
Downsides - we allocate a tiny bit more memory for unused ports, upside we've
removed as much code as it saved for most users..
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The multiple drivers share the minor space occupied by a particular major
number, the actual index within the device name's space is indicated by
the tty_driver->name_base + uart_port->line
Another usable formula is (uart_driver->minor - MINOR_BASE) + port->line
Use those to print the device names properly in such situations in
serial_core.c and 8250.c
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch the serial_core based drivers to use the new tty_port structure.
We can't quite use all of it yet because of the dynamically allocated
extras in the serial_core layer.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Serial drivers using DMA (like the atmel_serial driver) tend to get very
confused when the xmit buffer is flushed and nobody told them. They
also tend to spew a lot of garbage since the DMA engine keeps running
after the buffer is flushed and possibly refilled with unrelated data.
This patch adds a new flush_buffer operation to the uart_ops struct,
along with a call to it from uart_flush_buffer() right after the xmit
buffer has been cleared. The driver can implement this in order to
syncronize its internal DMA state with the xmit buffer when the buffer
is flushed.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported by Vipul Gandhi, the current serial_match_port() doesn't work
for tty-devices using dynamic major number allocation. Fix it.
It oopses if you suspend a serial port with _dynamic_ major number. ATM,
I think, there's only the drivers/serial/jsm/jsm_driver.c driver, that
does it in-tree.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: Vipul Gandhi <vcgandhi1@aol.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 64e9159f5d ("serial_core:
uart_set_ldisc infrastructure") introduced the ability for low-level
serial drivers to be informed when the tty ldisc changes.
However, the actual tty-layer function that does this callback for
serial devices was declared with the wrong type, having a spurious and
unused 'ldisc' argument.
This fixed the resulting compiler warning by just removing it.
Acked-by: Blithering Idiot <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The tty layer provides a callback that is used when the line discipline
is changed. Some hardware uses this to configure hardware specific
features such as IrDA mode on serial ports. Unfortunately the serial
layer does not provide this feature or pass it down to drivers.
Blackfin used to hack around this by rewriting the tty ops, but those are
now properly shared and const so the hack fails. Instead provide the
proper operations.
This change plus a follow up from the Blackfin guys is needed to avoid
blackfin losing features in this release.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
enable_irq_wake() and disable_irq_wake() need to be balanced. However,
serial_core.c calls these for different conditions during the suspend and
resume functions...
This is causing a regular WARN_ON() as found at
http://www.kerneloops.org/search.php?search=set_irq_wake
This patch makes the conditions for triggering the _wake enable/disable
sequence identical.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed that
static void uart_flush_buffer(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->port;
unsigned long flags;
/*
* This means you called this function _after_ the port was
* closed. No cookie for you.
*/
if (!state || !state->info) {
WARN_ON(1);
return;
}
is too late for checking state != NULL.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Operations are now a shared const function block as with most other Linux
objects
- Introduce wrappers for some optional functions to get consistent behaviour
- Wrap put_char which used to be patched by the tty layer
- Document which functions are needed/optional
- Make put_char report success/fail
- Cache the driver->ops pointer in the tty as tty->ops
- Remove various surplus lock calls we no longer need
- Remove proc_write method as noted by Alexey Dobriyan
- Introduce some missing sanity checks where certain driver/ldisc
combinations would oops as they didn't check needed methods were present
[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of checking for the BKL in these methods, take it ourselves. That
avoids propogating it into the serial drivers and we can then fix them later
on.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Russell King noticed this one: We have to avoid replacing B0 when we pick a
baud rate for a "hung up" port. Ugly but the proper fix is in the tty layer
and means changing the tty<->serial interfaces so we will defer that for now.
[akpm@linux-foundation.org: fix uninitialised var]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch (as1059) fixes a mistake in the way the serial core
initializes a device's wakeup settings. It should use the accessor
routine instead of relying on a macro producing an lvalue.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
