kernel_optimize_test/include
Alan Stern 6d88e67925 USB: don't stop root-hub status polls too soon
This patch (as1390) fixes a problem that crops up when a UHCI host
controller is unbound from uhci-hcd while there are still some active
URBs.  The URBs have to be unlinked when the root hub is unregistered,
and uhci-hcd relies upon root-hub status polls as part of its
unlinking procedure.  But usb_hcd_poll_rh_status() won't make those
status calls if hcd->rh_registered is clear, and the flag is cleared
_before_ the unregistration takes place.

Since hcd->rh_registered is used for other things and needs to be
cleared early, the solution is to add a new flag (rh_pollable) and use
it instead.  It gets cleared _after_ the root hub is unregistered.

Now that the status polls don't end too soon, we have to make sure
they also don't occur too late -- after the root hub's usb_device
structure or the HCD's private structures are deallocated.  Therefore
the patch adds usb_get_device() and usb_put_device() calls to protect
the root hub structure, and it adds an extra del_timer_sync() to
prevent the root-hub timer from causing an unexpected status poll.

This additional complexity would not be needed if the HCD framework
had provided separate stop() and release() callbacks instead of just
stop().  This lack could be fixed at some future time (although it
would require changes to every host controller driver); when that
happens this patch won't be needed any more.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 14:35:33 -07:00
..
acpi Merge branch 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2010-08-07 17:08:30 -07:00
asm-generic Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux 2010-08-10 12:07:51 -07:00
crypto
drm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2010-08-07 12:42:58 -07:00
keys DNS: Separate out CIFS DNS Resolver code 2010-08-05 17:17:51 +00:00
linux USB: don't stop root-hub status polls too soon 2010-08-10 14:35:33 -07:00
math-emu
media V4L/DVB: dib0700: break keytable into NEC and RC-5 variants 2010-08-02 16:43:49 -03:00
mtd mtd: Update copyright notices 2010-08-08 20:58:20 +01:00
net Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-08-06 13:30:43 -07:00
pcmcia pcmcia: use struct resource for PCMCIA devices, part 2 2010-08-03 09:04:16 +02:00
rdma IB: Rename RAW_ETY to RAW_ETHERTYPE 2010-08-04 10:44:19 -07:00
rxrpc
scsi
sound Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 2010-08-07 17:07:31 -07:00
trace memcg: add mm_vmscan_memcg_isolate tracepoint 2010-08-09 20:45:03 -07:00
video
xen
Kbuild