[Intel-gfx] [PATCH] drm/i915: Apply HWSTAM workaround for BSD ring on SandyBridge

[Chris Wilson]

...we need to apply exactly the same workaround for missing interrupts
from BSD as for the BLT ring, apparently.

See also commit 498e720b96379d8ee9c294950a01534a73defcf3
(drm/i915: Fix gen6 (SNB) missed BLT ring interrupts).

Reported-and-tested-by: nkalkhof at web.de
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38529
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_irq.c |    1 +
 drivers/gpu/drm/i915/i915_reg.h |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 9e34a1a..ae2b499 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1749,6 +1749,7 @@ void ironlake_irq_preinstall(struct drm_device *dev)
 		 * happens.
 		 */
 		I915_WRITE(GEN6_BLITTER_HWSTAM, ~GEN6_BLITTER_USER_INTERRUPT);
+		I915_WRITE(GEN6_BSD_HWSTAM, ~GEN6_BSD_USER_INTERRUPT);
 	}
 
 	/* XXX hotplug from PCH */
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2f967af..5d5def7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -531,6 +531,7 @@
 #define   GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_ENABLE		0
 #define   GEN6_BSD_SLEEP_PSMI_CONTROL_IDLE_INDICATOR			(1 << 3)
 
+#define GEN6_BSD_HWSTAM			0x12098
 #define GEN6_BSD_IMR			0x120a8
 #define   GEN6_BSD_USER_INTERRUPT	(1 << 12)
 
-- 
1.7.5.4