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. > > This issue has been introduced in > > commit a93fad0f7fb8a3ff12e8814b630648f6d187954c > Author: Vandana Kannan <vandana.kannan@xxxxxxxxx> > Date: Sat Jan 10 02:25:59 2015 +0530 > > drm/i915: DRRS calls based on frontbuffer > > v2: Don't blow up on uninitialized mutex and work item by checking > whether DRRS is support or not first. Also unconditionally initialize > the mutex/work item to avoid future trouble. > > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Cc: Ramalingam C <ramalingam.c@xxxxxxxxx> > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > Cc: Vandana Kannan <vandana.kannan@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx (4.0+ only) > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Happier, Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Tested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> -Chris -- Chris Wilson, Intel Open Source Technology Centre -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html