On Mon, Mar 06, 2017 at 11:15:28AM +0000, Chris Wilson wrote: > On Mon, Mar 06, 2017 at 12:01:51AM +0100, Pavel Machek wrote: > > Hi! > > > > > > mplayer stopped working after a while. Dmesg says: > > > > > > > > [ 3000.266533] cdc_ether 2-1.2:1.0 usb0: register 'cdc_ether' at > > > > Now I'm pretty sure it is a regression in v4.11-rc0. Any ideas what to > > try? Bisect will be slow and nasty :-(. > > I came the conclusion that #99671 is the ring HEAD overtaking the TAIL, > and under the presumption that your bug matches (as the symptoms do): > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c > index 4ffa35faff49..62e31a7438ac 100644 > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c > @@ -782,10 +782,10 @@ static void i9xx_submit_request(struct drm_i915_gem_request *request) > { > struct drm_i915_private *dev_priv = request->i915; > > - i915_gem_request_submit(request); > - > GEM_BUG_ON(!IS_ALIGNED(request->tail, 8)); > I915_WRITE_TAIL(request->engine, request->tail); > + > + i915_gem_request_submit(request); Hmm. request->tail is not set until i915_gem_request_submit() Uh oh. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel