[PATCH 4.19 317/321] ASoC: stm32: i2s: fix IRQ clearing

[Greg Kroah-Hartman]

From: Olivier Moysan <olivier.moysan@xxxxxx>

commit 8ba3c5215d69c09f5c39783ff3b78347769822ad upstream.

Because of regmap cache, interrupts may not be cleared
as expected.
Declare IFCR register as write only and make writings
to IFCR register unconditional.

Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 sound/soc/stm/stm32_i2s.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

--- a/sound/soc/stm/stm32_i2s.c
+++ b/sound/soc/stm/stm32_i2s.c
@@ -246,8 +246,8 @@ static irqreturn_t stm32_i2s_isr(int irq
 		return IRQ_NONE;
 	}
 
-	regmap_update_bits(i2s->regmap, STM32_I2S_IFCR_REG,
-			   I2S_IFCR_MASK, flags);
+	regmap_write_bits(i2s->regmap, STM32_I2S_IFCR_REG,
+			  I2S_IFCR_MASK, flags);
 
 	if (flags & I2S_SR_OVR) {
 		dev_dbg(&pdev->dev, "Overrun\n");
@@ -276,7 +276,6 @@ static bool stm32_i2s_readable_reg(struc
 	case STM32_I2S_CFG2_REG:
 	case STM32_I2S_IER_REG:
 	case STM32_I2S_SR_REG:
-	case STM32_I2S_IFCR_REG:
 	case STM32_I2S_TXDR_REG:
 	case STM32_I2S_RXDR_REG:
 	case STM32_I2S_CGFR_REG:
@@ -547,8 +546,8 @@ static int stm32_i2s_startup(struct snd_
 	i2s->refcount++;
 	spin_unlock(&i2s->lock_fd);
 
-	return regmap_update_bits(i2s->regmap, STM32_I2S_IFCR_REG,
-				  I2S_IFCR_MASK, I2S_IFCR_MASK);
+	return regmap_write_bits(i2s->regmap, STM32_I2S_IFCR_REG,
+				 I2S_IFCR_MASK, I2S_IFCR_MASK);
 }
 
 static int stm32_i2s_hw_params(struct snd_pcm_substream *substream,
@@ -603,8 +602,8 @@ static int stm32_i2s_trigger(struct snd_
 			return ret;
 		}
 
-		regmap_update_bits(i2s->regmap, STM32_I2S_IFCR_REG,
-				   I2S_IFCR_MASK, I2S_IFCR_MASK);
+		regmap_write_bits(i2s->regmap, STM32_I2S_IFCR_REG,
+				  I2S_IFCR_MASK, I2S_IFCR_MASK);
 
 		if (playback_flg) {
 			ier = I2S_IER_UDRIE;