From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jani Nikula <jani.nikula@linux.intel.com>
Subject: Re: [Intel-gfx] [PATCH 1/2] drm/i915: Fix locking in DRRS	flush/invalidate hooks
Date: Fri, 10 Apr 2015 14:33:09 +0300
Message-ID: <87fv88qkui.fsf@intel.com>
References: <1428570631-11009-1-git-send-email-daniel.vetter@ffwll.ch> <1428590656-24933-1-git-send-email-daniel.vetter@ffwll.ch> <20150409163910.GC20904@nuc-i3427.alporthouse.com>
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To: Chris Wilson <chris@chris-wilson.co.uk>, Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>, "4.0+ only" <stable@vger.kernel.org>, Rodrigo Vivi <rodrigo.vivi@intel.com>, Daniel Vetter <daniel.vetter@intel.com>
List-Id: intel-gfx@lists.freedesktop.org

On Thu, 09 Apr 2015, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Thu, Apr 09, 2015 at 04:44:15PM +0200, Daniel Vetter wrote:
>> We must acquire the mutex before we can check drrs.dp, otherwise
>> someone might sneak in with a modeset, clear the pointer after we've
>> checked it and then the code will Oops.
>>=20
>> This issue has been introduced in
>>=20
>> commit a93fad0f7fb8a3ff12e8814b630648f6d187954c
>> Author: Vandana Kannan <vandana.kannan@intel.com>
>> Date:   Sat Jan 10 02:25:59 2015 +0530
>>=20
>>     drm/i915: DRRS calls based on frontbuffer
>>=20
>> v2: Don't blow up on uninitialized mutex and work item by checking
>> whether DRRS is support or not first. Also unconditionally initializ=
e
>> the mutex/work item to avoid future trouble.
>>=20
>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>> Cc: Ville Syrj=C3=A4l=C3=A4 <ville.syrjala@linux.intel.com>
>> Cc: Ramalingam C <ramalingam.c@intel.com>
>> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
>> Cc: Vandana Kannan <vandana.kannan@intel.com>
>> Cc: stable@vger.kernel.org (4.0+ only)
>> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
>
> Happier,
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> Tested-by: Chris Wilson <chris@chris-wilson.co.uk>

Both pushed to drm-intel-next-fixes, thanks for the patch and review.

BR,
Jani.

> -Chris
>
> --=20
> Chris Wilson, Intel Open Source Technology Centre
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--=20
Jani Nikula, Intel Open Source Technology Center