[Intel-gfx] [PATCH v2] drm/i915/irq: Clear GFX_MSTR_IRQ as part of IRQ reset

[Gustavo Sousa]

Starting with Xe_LP+, GFX_MSTR_IRQ contains status bits that have W1C
behavior. If we do not properly reset them, we would miss delivery of
interrupts if a pending bit is set when enabling IRQs.

As an example, the display part of our probe routine contains paths
where we wait for vblank interrupts. If a display interrupt was already
pending when enabling IRQs, we would time out waiting for the vblank.

Avoid the potential issue by clearing GFX_MSTR_IRQ as part of the IRQ
reset.

v2:
  - Move logic from gen11_gt_irq_reset() to dg1_irq_reset(). (Matt)

BSpec: 50875, 54028
Cc: Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 1bfcfbe6e30b..8130f043693b 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -751,6 +751,8 @@ static void dg1_irq_reset(struct drm_i915_private *dev_priv)
 
 	GEN3_IRQ_RESET(uncore, GEN11_GU_MISC_);
 	GEN3_IRQ_RESET(uncore, GEN8_PCU_);
+
+	intel_uncore_write(uncore, GEN11_GFX_MSTR_IRQ, ~0);
 }
 
 static void cherryview_irq_reset(struct drm_i915_private *dev_priv)
-- 
2.42.0