linux/drivers/media/dvb/cinergyT2
Oleg Nesterov 1e4597e8f0 V4L/DVB (5818): CinergyT2: fix flush_workqueue() vs work->func() deadlock
Spotted and tested by Thomas Sattler <tsattler@gmx.de>.

cinergyT2.c does cancel_delayed_work() + flush_scheduled_work() while
holding cinergyt2->sem. This leads to deadlock because work->func()
needs the same mutex to complete. Another bug is that this code in fact
can't reliably stop the re-arming delayed_work.

Convert this code to use cancel_rearming_delayed_work() and move it
out of ->sem. Another mutex, ->wq_sem, was added to protect against the
concurrent open/resume.

This patch is a horrible hack to fix the lockup which happens in practice.
As Dmitry Torokhov pointed out this driver has other problems and needs
further changes.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-07-03 15:11:19 -03:00
..
Kconfig Fix several typos in drivers/ 2006-10-03 22:31:37 +02:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cinergyT2.c V4L/DVB (5818): CinergyT2: fix flush_workqueue() vs work->func() deadlock 2007-07-03 15:11:19 -03:00