From: Stefan Agner <stefan@agner.ch>
Date: Tue, 5 Jan 2016 00:34:22 +0000 (-0800)
Subject: drm/fsl-dcu: do not update when modifying irq registers
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=34a515d27c6573b6f550877b30dd5e0f440c3d8f;p=linux.git

drm/fsl-dcu: do not update when modifying irq registers

The IRQ status and mask registers are not "double buffered" according
to the reference manual. Hence, there is no extra transfer/update
write needed when modifying these registers.

Signed-off-by: Stefan Agner <stefan@agner.ch>
---

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
index e04efbed1a54f..cc2fde2ae5eff 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
@@ -59,8 +59,6 @@ static int fsl_dcu_drm_irq_init(struct drm_device *dev)
 
 	regmap_write(fsl_dev->regmap, DCU_INT_STATUS, 0);
 	regmap_write(fsl_dev->regmap, DCU_INT_MASK, ~0);
-	regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-		     DCU_UPDATE_MODE_READREG);
 
 	return ret;
 }
@@ -139,8 +137,6 @@ static irqreturn_t fsl_dcu_drm_irq(int irq, void *arg)
 		drm_handle_vblank(dev, 0);
 
 	regmap_write(fsl_dev->regmap, DCU_INT_STATUS, int_status);
-	regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-		     DCU_UPDATE_MODE_READREG);
 
 	return IRQ_HANDLED;
 }