[PATCH 5.19 0107/1157] soundwire: qcom: Check device status before reading devid

Greg Kroah-Hartman
2022-08-15T22:21:47Z

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

commit aa1262ca66957183ea1fb32a067e145b995f3744 upstream.

As per hardware datasheet its recommended that we check the device
status before reading devid assigned by auto-enumeration.

Without this patch we see SoundWire devices with invalid enumeration
addresses on the bus.

Cc: stable@vger.kernel.org
Fixes: a6e6581942ca ("soundwire: qcom: add auto enumeration support")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220706095644.5852-1-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/soundwire/qcom.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -471,6 +471,10 @@ static int qcom_swrm_enumerate(struct sd
char *buf1 = (char *)&val1, *buf2 = (char *)&val2;

for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+ /* do not continue if the status is Not Present */
+ if (!ctrl->status[i])
+ continue;
+
/*SCP_Devid5 - Devid 4*/
ctrl->reg_read(ctrl, SWRM_ENUMERATOR_SLAVE_DEV_ID_1(i), &val1);