Re: [PATCH] i915: remove pm_qos request on error

[Daniel Vetter <daniel@ffwll.ch>]

On Sat, Jan 25, 2014 at 10:13:37AM +0100, Stanislaw Gruszka wrote:
> Not removing pm qos request and free memory for it can cause crash,
> when some other driver use pm qos. For example, this oops:
> 
> BUG: unable to handle kernel paging request at fffffffffffffff8
> IP: [<ffffffff81307a6b>] plist_add+0x5b/0xd0
> Call Trace:
>  [<ffffffff810acf25>] pm_qos_update_target+0x125/0x1e0
>  [<ffffffff810ad071>] pm_qos_add_request+0x91/0x100
>  [<ffffffffa053ec14>] e1000_open+0xe4/0x5b0 [e1000e]
> 
> was caused by earlier i915 probe failure:
> 
> [drm:i915_report_and_clear_eir] *ERROR* EIR stuck: 0x00000010, masking
> [drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f001 head 00003004 tail 00000000 start 00003000
> [drm:i915_driver_load] *ERROR* failed to init modeset
> i915: probe of 0000:00:02.0 failed with error -5
> 
> Bug report:
> http://bugzilla.redhat.com/show_bug.cgi?id=1057533
> 
> Reported-by: Giandomenico De Tullio <ghisha@gmail.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>

Picked up for -fixes, thanks for the patch. I've remove the movement of
the to pm_qos_add_request though. If we want to clean this is I think an
intel_irq_fini which is called both here and in the unload code is better.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch