[PATCH] media: cec: stm32: return an error when log-address wait times out

[Pengpeng Hou]

stm32_cec_adap_log_addr() waits for TXSOM to clear before disabling CEC
and updating the logical address registers. The wait result is ignored,
so a timeout can still be reported as a successful logical address
update.

Return the polling error before touching the address registers. Compute
the address mask only for valid logical addresses so the invalid-address
path does not evaluate a shift based on CEC_LOG_ADDR_INVALID.

Signed-off-by: Pengpeng Hou <pengpeng at iscas.ac.cn>
---
 drivers/media/cec/platform/stm32/stm32-cec.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/media/cec/platform/stm32/stm32-cec.c b/drivers/media/cec/platform/stm32/stm32-cec.c
index 1ec0cece0..82709b5ec 100644
--- a/drivers/media/cec/platform/stm32/stm32-cec.c
+++ b/drivers/media/cec/platform/stm32/stm32-cec.c
@@ -193,18 +193,24 @@ static int stm32_cec_adap_enable(struct cec_adapter *adap, bool enable)
 static int stm32_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
 {
 	struct stm32_cec *cec = adap->priv;
-	u32 oar = (1 << logical_addr) << 16;
 	u32 val;
+	int ret;
 
 	/* Poll every 100µs the register CEC_CR to wait end of transmission */
-	regmap_read_poll_timeout(cec->regmap, CEC_CR, val, !(val & TXSOM),
-				 100, CEC_XFER_TIMEOUT_MS * 1000);
+	ret = regmap_read_poll_timeout(cec->regmap, CEC_CR, val, !(val & TXSOM),
+				       100, CEC_XFER_TIMEOUT_MS * 1000);
+	if (ret)
+		return ret;
+
 	regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
 
-	if (logical_addr == CEC_LOG_ADDR_INVALID)
-		regmap_update_bits(cec->regmap, CEC_CFGR, OAR, 0);
-	else
+	if (logical_addr == CEC_LOG_ADDR_INVALID) {
+		regmap_update_bits(cec->regmap, CEC_CFGR, OAR, 0);
+	} else {
+		u32 oar = BIT(logical_addr) << 16;
+
 		regmap_update_bits(cec->regmap, CEC_CFGR, oar, oar);
+	}
 
 	regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
 
-- 
2.50.1 (Apple Git-155)