Workaround Sandy Bridge GPU stalls by allowing the blitter command streamer
to write interrupt state to the Hardware Status Page when a MI_USER_INTERRUPT
command is decoded.
v1->v2: Moved to prior interrupt handler installation and RMW flags as per
feedback.
Eric, if you're happy, please sign-off and send to Dave for inclusion in -rc4
if possible. Further changes may be needed for -stable.
Signed-off-by: Daniel J Blueman <[email protected]>
---
drivers/gpu/drm/i915/i915_irq.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b9fafe3..b7f11a5 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1741,6 +1741,13 @@ void ironlake_irq_preinstall(struct drm_device *dev)
I915_WRITE(HWSTAM, 0xeffe);
+ if (IS_GEN6(dev))
+ /* workaround stalls observed on Sandy Bridge GPUs by
+ allowing the blitter command streamer to generate a
+ write to the Hardware Status Page for MI_USER_INTERRUPT */
+ I915_WRITE(GEN6_BLITTER_HWSTAM, I915_READ(GEN6_BLITTER_HWSTAM)
+ & ~GEN6_BLITTER_USER_INTERRUPT);
+
/* XXX hotplug from PCH */
I915_WRITE(DEIMR, 0xffffffff);
--
1.7.4.1
On 18 June 2011 01:44, Eric Anholt <[email protected]> wrote:
> On Sat, 18 Jun 2011 00:42:00 +0800, Daniel J Blueman <[email protected]> wrote:
>> Workaround Sandy Bridge GPU stalls by allowing the blitter command streamer
>> to write interrupt state to the Hardware Status Page when a MI_USER_INTERRUPT
>> command is decoded.
>>
>> v1->v2: Moved to prior interrupt handler installation and RMW flags as per
>> feedback.
>
> We shouldn't be RMWing. ?We're the driver, we're supposed to know what
> we want. ?I'm backing that bit out, will do another round of testing,
> and send it off.
I still prefer directly setting the mask due to my earlier reasons.
Unmasking in the IRQ preinstall tests good here, so I'll send a v3
patch in the morning.
Thanks,
Daniel
--
Daniel J Blueman
On Sat, 18 Jun 2011 02:20:08 +0800, Daniel J Blueman <[email protected]> wrote:
> On 18 June 2011 01:44, Eric Anholt <[email protected]> wrote:
> > On Sat, 18 Jun 2011 00:42:00 +0800, Daniel J Blueman <[email protected]> wrote:
> >> Workaround Sandy Bridge GPU stalls by allowing the blitter command streamer
> >> to write interrupt state to the Hardware Status Page when a MI_USER_INTERRUPT
> >> command is decoded.
> >>
> >> v1->v2: Moved to prior interrupt handler installation and RMW flags as per
> >> feedback.
> >
> > We shouldn't be RMWing. We're the driver, we're supposed to know what
> > we want. I'm backing that bit out, will do another round of testing,
> > and send it off.
>
> I still prefer directly setting the mask due to my earlier reasons.
> Unmasking in the IRQ preinstall tests good here, so I'll send a v3
> patch in the morning.
Already tested and sent v3 out to lkml.