From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Date: Wed, 6 Jul 2022 09:56:44 +0000 (+0100)
Subject: soundwire: qcom: Check device status before reading devid
X-Git-Tag: block-6.0-2022-08-12~26^2~9^2~1
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=aa1262ca6695;p=linux-block.git

soundwire: qcom: Check device status before reading devid

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>
---

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index fbc4c42f3cf3..b48815d77f8d 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -474,6 +474,10 @@ 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);