[PATCH v4 2/7] drm/tilcdc: Write to LCDC_END_OF_INT_IND_REG at the end of IRQ function

[Jyri Sarha]

Reorder the IRQ function so that the write to LCDC_END_OF_INT_IND_REG
is done last. The write to LCDC_END_OF_INT_IND_REG indicates to LCDC
that the interrupt service routine has completed (see section
13.3.6.1.6 in AM335x TRM). This is needed if LCDC's ipgvmodirq module
is configured for pulse interrupts.

Signed-off-by: Jyri Sarha <jsarha at ti.com>
---
 drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index 4d8f9a5..65284e9 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -725,30 +725,34 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
 			tilcdc_crtc->frame_intact = true;
 	}
 
+	if (stat & LCDC_FIFO_UNDERFLOW)
+		dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underfow",
+				    __func__, stat);
+
+	/* For revision 2 only */
 	if (priv->rev == 2) {
 		if (stat & LCDC_FRAME_DONE) {
 			tilcdc_crtc->frame_done = true;
 			wake_up(&tilcdc_crtc->frame_done_wq);
 		}
-		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
-	}
 
-	if (stat & LCDC_SYNC_LOST) {
-		dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
-				    __func__, stat);
-		tilcdc_crtc->frame_intact = false;
-		if (tilcdc_crtc->sync_lost_count++ > SYNC_LOST_COUNT_LIMIT) {
-			dev_err(dev->dev,
-				"%s(0x%08x): Sync lost flood detected, disabling the interrupt",
-				__func__, stat);
-			tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
-				     LCDC_SYNC_LOST);
+		if (stat & LCDC_SYNC_LOST) {
+			dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
+					    __func__, stat);
+			tilcdc_crtc->frame_intact = false;
+			if (tilcdc_crtc->sync_lost_count++ >
+			    SYNC_LOST_COUNT_LIMIT) {
+				dev_err(dev->dev, "%s(0x%08x): Sync lost flood detected, disabling the interrupt", __func__, stat);
+				tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
+					     LCDC_SYNC_LOST);
+			}
 		}
-	}
 
-	if (stat & LCDC_FIFO_UNDERFLOW)
-		dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underfow",
-				    __func__, stat);
+		/* Indicate to LCDC that the interrupt service routine has
+		 * completed, see 13.3.6.1.6 in AM335x TRM.
+		 */
+		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
+	}
 
 	return IRQ_HANDLED;
 }
-- 
1.9.1