[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