Re: [PATCH] thinkpad-acpi: fix potential suspend blocking issue

[Maciej Rutecki]

On wtorek, 5 marca 2013 o 18:34:43 Mandeep Singh Baines wrote:
> Fixes the following lockdep error:
> 
> [ BUG: ktpacpi_nvramd/446 still has locks held! ]
> 
> hotkey_kthread() calls set_freezable() after acquiring the
> hotkey_kthread_mutex(). set_freezable() calls try_to_freeze().
> This could block suspend if we were to freeze at this point
> and another task were to block on the mutex, potentially via
> writing to one of the sysfs attrs. This race is unlikely but
> can be easily fixed by moving the set_freezable() call.
> 
> Reported-by: Maciej Rutecki <maciej.rutecki@xxxxxxxxx>
> Signed-off-by: Mandeep Singh Baines <msb@xxxxxxxxxxxx>
> CC: Aaron Lu <aaron.lu@xxxxxxxxx>
> CC: Henrique de Moraes Holschuh <hmh@xxxxxxxxxx>
> CC: Tejun Heo <tj@xxxxxxxxxx>
> CC: Oleg Nesterov <oleg@xxxxxxxxxx>
> CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Maciej Rutecki <maciej.rutecki@xxxxxxxxx>

Patch fixes the problem. Thanks!

Regards

-- 
Maciej Rutecki
http://www.mrutecki.pl
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