From aa1262ca66957183ea1fb32a067e145b995f3744 Mon Sep 17 00:00:00 2001
From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Date: Wed, 6 Jul 2022 10:56:44 +0100
Subject: [PATCH] soundwire: qcom: Check device status before reading devid
Git-commit: aa1262ca66957183ea1fb32a067e145b995f3744
Patch-mainline: v6.0-rc1
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/soundwire/qcom.c | 4 ++++
 1 file changed, 4 insertions(+)

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);
 
-- 
2.35.3