drm/msm/dpu: don't clear IRQ register twice

We already clear the IRQ status register before processing IRQs, so do
not clear the register again. Especially do not clear the IRQ status
_after_ processing the IRQ as this way we can loose the event.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/20210617222029.463045-3-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c

@@ -120,21 +120,6 @@ static const struct dpu_intr_reg dpu_intr_set[] = {
 #define DPU_IRQ_REG(irq_idx)	(irq_idx / 32)
 #define DPU_IRQ_MASK(irq_idx)	(BIT(irq_idx % 32))
 
-static void dpu_hw_intr_clear_intr_status_nolock(struct dpu_hw_intr *intr,
-		int irq_idx)
-{
-	int reg_idx;
-
-	if (!intr)
-		return;
-
-	reg_idx = DPU_IRQ_REG(irq_idx);
-	DPU_REG_WRITE(&intr->hw, dpu_intr_set[reg_idx].clr_off, DPU_IRQ_MASK(irq_idx));
-
-	/* ensure register writes go through */
-	wmb();
-}
-
 /**
  * dpu_core_irq_callback_handler - dispatch core interrupts
  * @arg:		private data of callback handler
@@ -203,8 +188,6 @@ irqreturn_t dpu_core_irq(struct dpu_kms *dpu_kms)
 
 			dpu_core_irq_callback_handler(dpu_kms, irq_idx);
 
-			dpu_hw_intr_clear_intr_status_nolock(intr, irq_idx);
-
 			/*
 			 * When callback finish, clear the irq_status
 			 * with the matching mask. Once irq_status