drm/i915: Fix IRQ stall issue on Ironlake
The master irq control in DE must be disabled before irq handling,
and enable after the process. This fixes the irq stall issue on
Ironlake.
Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zou, Nanhai <nanhai.zou@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index c3ceffa..aa7fd82 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -254,10 +254,15 @@
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
int ret = IRQ_NONE;
- u32 de_iir, gt_iir;
+ u32 de_iir, gt_iir, de_ier;
u32 new_de_iir, new_gt_iir;
struct drm_i915_master_private *master_priv;
+ /* disable master interrupt before clearing iir */
+ de_ier = I915_READ(DEIER);
+ I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL);
+ (void)I915_READ(DEIER);
+
de_iir = I915_READ(DEIIR);
gt_iir = I915_READ(GTIIR);
@@ -290,6 +295,9 @@
gt_iir = new_gt_iir;
}
+ I915_WRITE(DEIER, de_ier);
+ (void)I915_READ(DEIER);
+
return ret;
}