[PATCH v2 08/10] ASoC: fsl_sai: Check regmap_read() return value in ISR

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

The IRQ is shared, so fsl_sai_isr() may run while the SAI is runtime
suspended. The regmap is then in cache-only mode, so regmap_read()
fails and xcsr is used uninitialized.

Check the return value of regmap_read() for both TCSR and RCSR, and
skip the handling of the corresponding direction on failure.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---
 sound/soc/fsl/fsl_sai.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 25243b6859d6..5c50ed7c2258 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -148,7 +148,8 @@ static irqreturn_t fsl_sai_isr(int irq, void *devid)
 	mask = (FSL_SAI_FLAGS >> FSL_SAI_CSR_xIE_SHIFT) << FSL_SAI_CSR_xF_SHIFT;
 
 	/* Tx IRQ */
-	regmap_read(sai->regmap, FSL_SAI_TCSR(ofs), &xcsr);
+	if (regmap_read(sai->regmap, FSL_SAI_TCSR(ofs), &xcsr))
+		return IRQ_NONE;
 	flags = xcsr & mask;
 
 	if (flags)
@@ -179,7 +180,8 @@ static irqreturn_t fsl_sai_isr(int irq, void *devid)
 
 irq_rx:
 	/* Rx IRQ */
-	regmap_read(sai->regmap, FSL_SAI_RCSR(ofs), &xcsr);
+	if (regmap_read(sai->regmap, FSL_SAI_RCSR(ofs), &xcsr))
+		goto out;
 	flags = xcsr & mask;
 
 	if (flags)
-- 
2.43.0