From: Daniel Vetter Date: Wed, 25 Jan 2012 13:04:00 +0000 (+0100) Subject: drm/i915: enable forcewake voodoo also for gen6 X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=99ffa1629d737295e569267cf5940758139f9ddb;p=deliverable%2Flinux.git drm/i915: enable forcewake voodoo also for gen6 We still have reports of missed irqs even on Sandybridge with the HWSTAM workaround in place. Testing by the bug reporter gets rid of them with the forcewake voodoo and no HWSTAM writes. Because I've slightly botched the rebasing I've left out the ACTHD readback which is also required to get IVB working. Seems to still work on the tester's machine, so I think we should go with the more minmal approach on SNB. Especially since I've only found weak evidence for holding forcewake while waiting for an interrupt to arrive, but none for the ACTHD readback. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45181 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45332 Tested-by: Nicolas Kalkhof nkalkhof()at()web.de Acked-by: Chris Wilson Signed-Off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 063b4577d4c6..bd6168be63d3 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1785,18 +1785,6 @@ static void ironlake_irq_preinstall(struct drm_device *dev) I915_WRITE(HWSTAM, 0xeffe); - if (IS_GEN6(dev)) { - /* Workaround stalls observed on Sandy Bridge GPUs by - * making the blitter command streamer generate a - * write to the Hardware Status Page for - * MI_USER_INTERRUPT. This appears to serialize the - * previous seqno write out before the interrupt - * happens. - */ - I915_WRITE(GEN6_BLITTER_HWSTAM, ~GEN6_BLITTER_USER_INTERRUPT); - I915_WRITE(GEN6_BSD_HWSTAM, ~GEN6_BSD_USER_INTERRUPT); - } - /* XXX hotplug from PCH */ I915_WRITE(DEIMR, 0xffffffff); diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 8a983b50a791..e784ebb8cc27 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -798,8 +798,7 @@ gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag) /* It looks like we need to prevent the gt from suspending while waiting * for an notifiy irq, otherwise irqs seem to get lost on at least the * blt/bsd rings on ivb. */ - if (IS_GEN7(dev)) - gen6_gt_force_wake_get(dev_priv); + gen6_gt_force_wake_get(dev_priv); spin_lock(&ring->irq_lock); if (ring->irq_refcount++ == 0) { @@ -826,8 +825,7 @@ gen6_ring_put_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag) } spin_unlock(&ring->irq_lock); - if (IS_GEN7(dev)) - gen6_gt_force_wake_put(dev_priv); + gen6_gt_force_wake_put(dev_priv); } static bool