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fbc9f97bbf
Calling cancel_delayed_work() from inside
spin_lock_irqsave, introduces a potential deadlock.
As explained by Johannes Berg <johannes@sipsolutions.net>
A - lock
T - timer
phase CPU 1 CPU 2
---------------------------------------------
some place that calls
cancel_timer_sync()
(which is the | code)
lock-irq(A)
| "lock-irq"(T)
| "unlock"(T)
| wait(T)
unlock(A)
timer softirq
"lock"(T)
run(T)
"unlock"(T)
irq handler
lock(A)
unlock(A)
Now all that again, interleaved, leading to deadlock:
lock-irq(A)
"lock"(T)
run(T)
IRQ during or maybe
before run(T) --> lock(A)
"lock-irq"(T)
wait(T)
We fix this by moving the call to cancel_delayed_work() into workqueue.
There are cases where the work may not actually be queued or running
at the time we are trying to cancel it, but cancel_delayed_work() is
able to deal with this.
Also cleanup iwl_set_mode related to this call. This function
(iwl_set_mode) is only called when bringing interface up and there will
thus not be any scanning done. No need to try to cancel scanning.
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13224, which was also
reported at http://marc.info/?l=linux-wireless&m=124081921903223&w=2 .
Tested-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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| .. | ||
| iwl3945-base.c | ||
| iwl-1000.c | ||
| iwl-3945-fh.h | ||
| iwl-3945-hw.h | ||
| iwl-3945-led.c | ||
| iwl-3945-led.h | ||
| iwl-3945-rs.c | ||
| iwl-3945.c | ||
| iwl-3945.h | ||
| iwl-4965-hw.h | ||
| iwl-4965.c | ||
| iwl-5000-hw.h | ||
| iwl-5000.c | ||
| iwl-6000-hw.h | ||
| iwl-6000.c | ||
| iwl-agn-rs.c | ||
| iwl-agn-rs.h | ||
| iwl-agn.c | ||
| iwl-calib.c | ||
| iwl-calib.h | ||
| iwl-commands.h | ||
| iwl-core.c | ||
| iwl-core.h | ||
| iwl-csr.h | ||
| iwl-debug.h | ||
| iwl-debugfs.c | ||
| iwl-dev.h | ||
| iwl-eeprom.c | ||
| iwl-eeprom.h | ||
| iwl-fh.h | ||
| iwl-hcmd.c | ||
| iwl-helpers.h | ||
| iwl-io.h | ||
| iwl-led.c | ||
| iwl-led.h | ||
| iwl-power.c | ||
| iwl-power.h | ||
| iwl-prph.h | ||
| iwl-rfkill.c | ||
| iwl-rfkill.h | ||
| iwl-rx.c | ||
| iwl-scan.c | ||
| iwl-spectrum.c | ||
| iwl-spectrum.h | ||
| iwl-sta.c | ||
| iwl-sta.h | ||
| iwl-tx.c | ||
| Kconfig | ||
| Makefile | ||