[Intel-gfx] [PATCH 20/24] drm/i915: kill bogus GTIIR clearing in vlv_preinstall hook

[Daniel Vetter]

Preinstall disables interrupts, we clear the status register in the
postinstall hook before we actually enable interrupt sources.

Also add a comment for the curios ring IMR masking, it doesn't
seem to be required on any other platform.

We seem to have some room for common gt_preinstall/postinstall hooks.

Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_irq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 293ee68..b680e1c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2546,13 +2546,12 @@ static void valleyview_irq_preinstall(struct drm_device *dev)
 
 	/* VLV magic */
 	I915_WRITE(VLV_IMR, 0);
+	/* Do we really need to clear ring masks for vlv? */
 	I915_WRITE(RING_IMR(RENDER_RING_BASE), 0);
 	I915_WRITE(RING_IMR(GEN6_BSD_RING_BASE), 0);
 	I915_WRITE(RING_IMR(BLT_RING_BASE), 0);
 
 	/* and GT */
-	I915_WRITE(GTIIR, I915_READ(GTIIR));
-	I915_WRITE(GTIIR, I915_READ(GTIIR));
 	I915_WRITE(GTIMR, 0xffffffff);
 	I915_WRITE(GTIER, 0x0);
 	POSTING_READ(GTIER);
-- 
1.8.1.4