| Message ID | alpine.LNX.2.00.1408071445250.6219@pobox.suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 7 Aug 2014, Jiri Kosina wrote: > The patch below seems to finally cure the problem at my system; I've just > attached it to freedesktop bugzilla, but sending it to this thread as well > to hopefully get as much testing coverage by affected people as possible. > > I am going on with testing whether it really completely fixes the problem > or just made it less likely. Okay, after 31 suspend-resume cycles, the problem appeared again (while without the patch, it triggers with 100% reliability). So it's not a complete fix, it just makes the problem much less visible. Going back to bugzilla discussion. > > From: Jiri Kosina <jkosina@suse.cz> > Subject: [PATCH] drm/i915: read HEAD register back in init_ring_common() to enforce ordering > > Withtout this, ring initialization fails reliabily during resume with > > [drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f001 head ffffff8804 tail 00000000 start 000e4000 > > Signed-off-by: Jiri Kosina <jkosina@suse.cz> > --- > drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c > index 279488a..7add7ee 100644 > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c > @@ -517,6 +517,9 @@ static int init_ring_common(struct intel_engine_cs *ring) > else > ring_setup_phys_status_page(ring); > > + /* Enforce ordering by reading HEAD register back */ > + I915_READ_HEAD(ring); > + > /* Initialize the ring. This must happen _after_ we've cleared the ring > * registers with the above sequence (the readback of the HEAD registers > * also enforces ordering), otherwise the hw might lose the new ring
On Thu, Aug 07, 2014 at 02:47:21PM +0200, Jiri Kosina wrote: > On Fri, 11 Jul 2014, Pavel Machek wrote: > > > > > > Ok, so I have set up machines for ktest / autobisect, and found out that > > > > > 3.16-rc1 no longer has that problem. Oh well, bisect would not be fun, > > > > > anyway... > > > > > > > > I am still seeing the problem with 3.16-rc2. > > > > > > I'm confused now. Is the bisect result > > > > > > commit 773875bfb6737982903c42d1ee88cf60af80089c > > > Author: Daniel Vetter <daniel.vetter@ffwll.ch> > > > Date: Mon Jan 27 10:00:30 2014 +0100 > > > > > > drm/i915: Don't set the 8to6 dither flag when not scaling > > > > > > now the culprit or not? Or do we have 2 different bugs at hand here? > > > > Three different issues, it seems. Two ring initialization problems, > > one went away in 3.16 (for me), second did not (suspend for jikos), > > third -- trivial issue with 8to6 dither. > > The patch below seems to finally cure the problem at my system; I've just > attached it to freedesktop bugzilla, but sending it to this thread as well > to hopefully get as much testing coverage by affected people as possible. > > I am going on with testing whether it really completely fixes the problem > or just made it less likely. Picked up for -fixes, thanks for the patch. -Daniel > > > > > > From: Jiri Kosina <jkosina@suse.cz> > Subject: [PATCH] drm/i915: read HEAD register back in init_ring_common() to enforce ordering > > Withtout this, ring initialization fails reliabily during resume with > > [drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f001 head ffffff8804 tail 00000000 start 000e4000 > > Signed-off-by: Jiri Kosina <jkosina@suse.cz> > --- > drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c > index 279488a..7add7ee 100644 > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c > @@ -517,6 +517,9 @@ static int init_ring_common(struct intel_engine_cs *ring) > else > ring_setup_phys_status_page(ring); > > + /* Enforce ordering by reading HEAD register back */ > + I915_READ_HEAD(ring); > + > /* Initialize the ring. This must happen _after_ we've cleared the ring > * registers with the above sequence (the readback of the HEAD registers > * also enforces ordering), otherwise the hw might lose the new ring > > -- > Jiri Kosina > SUSE Labs > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 279488a..7add7ee 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -517,6 +517,9 @@ static int init_ring_common(struct intel_engine_cs *ring) else ring_setup_phys_status_page(ring); + /* Enforce ordering by reading HEAD register back */ + I915_READ_HEAD(ring); + /* Initialize the ring. This must happen _after_ we've cleared the ring * registers with the above sequence (the readback of the HEAD registers * also enforces ordering), otherwise the hw might lose the new ring