drm/msm: Pass interrupt status to a5xx_rbbm_err_irq()

The interrupt status was being cleared before processing the handlers.
a5xx_rbbm_err_irq() was checking the interrupt status again, which would
likely turn out bad because the interrupt status would be 0 (or at least
different). Pass the original status to the function instead.

Also, skip clearing RBBM_AHB_ERROR from the interrupt status. The interrupt
will keep firing until the error source is cleared.  Skip the clear to
avoid a storm until the error is cleared in a5xx_rbbm_err_irq().
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/adreno/a5xx_gpu.c

@@ -638,10 +638,8 @@ static void a5xx_cp_err_irq(struct msm_gpu *gpu)
 	}
 }
 
-static void a5xx_rbbm_err_irq(struct msm_gpu *gpu)
+static void a5xx_rbbm_err_irq(struct msm_gpu *gpu, u32 status)
 {
-	u32 status = gpu_read(gpu, REG_A5XX_RBBM_INT_0_STATUS);
-
 	if (status & A5XX_RBBM_INT_0_MASK_RBBM_AHB_ERROR) {
 		u32 val = gpu_read(gpu, REG_A5XX_RBBM_AHB_ERROR_STATUS);
 
@@ -653,6 +651,10 @@ static void a5xx_rbbm_err_irq(struct msm_gpu *gpu)
 
 		/* Clear the error */
 		gpu_write(gpu, REG_A5XX_RBBM_AHB_CMD, (1 << 4));
+
+		/* Clear the interrupt */
+		gpu_write(gpu, REG_A5XX_RBBM_INT_CLEAR_CMD,
+			A5XX_RBBM_INT_0_MASK_RBBM_AHB_ERROR);
 	}
 
 	if (status & A5XX_RBBM_INT_0_MASK_RBBM_TRANSFER_TIMEOUT)
@@ -704,10 +706,16 @@ static irqreturn_t a5xx_irq(struct msm_gpu *gpu)
 {
 	u32 status = gpu_read(gpu, REG_A5XX_RBBM_INT_0_STATUS);
 
-	gpu_write(gpu, REG_A5XX_RBBM_INT_CLEAR_CMD, status);
+	/*
+	 * Clear all the interrupts except RBBM_AHB_ERROR - if we clear it
+	 * before the source is cleared the interrupt will storm.
+	 */
+	gpu_write(gpu, REG_A5XX_RBBM_INT_CLEAR_CMD,
+		status & ~A5XX_RBBM_INT_0_MASK_RBBM_AHB_ERROR);
 
+	/* Pass status to a5xx_rbbm_err_irq because we've already cleared it */
 	if (status & RBBM_ERROR_MASK)
-		a5xx_rbbm_err_irq(gpu);
+		a5xx_rbbm_err_irq(gpu, status);
 
 	if (status & A5XX_RBBM_INT_0_MASK_CP_HW_ERROR)
 		a5xx_cp_err_irq(gpu);