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 --- drivers/soundwire/qcom.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c index dbf793e7e5d7..9df970eeca45 100644 --- a/drivers/soundwire/qcom.c +++ b/drivers/soundwire/qcom.c @@ -480,6 +480,10 @@ static int qcom_swrm_enumerate(struct sdw_bus *bus) 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);