[Intel-gfx] [PATCH] drm/i915: Disable display interrupts during display IRQ handler

[clinton.a.taylor at intel.com]

From: Clint Taylor <clinton.a.taylor at intel.com>

During the Display Interrupt Service routine the Display Interrupt
Enable bit must be disabled, The interrupts handled, then the
Display Interrupt Enable bit must be set to prevent possible missed
interrupts.

Bspec: 49212
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Aditya Swarup <aditya.swarup at intel.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Clint Taylor <clinton.a.taylor at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index dae00f7dd7df..43434273a08a 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2484,7 +2484,11 @@ __gen11_irq_handler(struct drm_i915_private * const i915,
 		 * GEN11_DISPLAY_INT_CTL has same format as GEN8_MASTER_IRQ
 		 * for the display related bits.
 		 */
+		raw_reg_write(regs, GEN11_DISPLAY_INT_CTL, 0x0);
 		gen8_de_irq_handler(i915, disp_ctl);
+		raw_reg_write(regs, GEN11_DISPLAY_INT_CTL,
+					  GEN11_DISPLAY_IRQ_ENABLE);
+
 		enable_rpm_wakeref_asserts(&i915->runtime_pm);
 	}
 
-- 
2.19.1