From: Jyri Sarha <jsarha@ti.com>
Date: Thu, 7 Apr 2016 17:36:48 +0000 (+0300)
Subject: drm/tilcdc: Write to LCDC_END_OF_INT_IND_REG at the end of IRQ function
X-Git-Tag: v4.14-rc1~2243^2~46^2~26
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=149441134c4ae4ebff393ca113f0941842385a6b;p=platform%2Fkernel%2Flinux-rpi.git

drm/tilcdc: Write to LCDC_END_OF_INT_IND_REG at the end of IRQ function

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@ti.com>
---

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index 45ce0ba..55b8472 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -725,12 +725,16 @@ 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",
@@ -743,11 +747,12 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
 					     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;
 }