[PATCH v5 10/25] soundwire: amd: return response on IMM status cleanup timeout

[Vijendar Mukunda <Vijendar.Mukunda@amd.com>]

amd_sdw_send_cmd_get_resp() reads the hardware response after
IMM_RES_VALID is set, then writes IMM_RES_VALID to acknowledge and
polls until the bit clears (status cleanup handshake).

When the cleanup poll timed out, the code returned the error without
writing *response, causing callers to report SDW_CMD_TIMEOUT and
discard a valid response - upper_resp and lower_resp had already been
read before the cleanup write.

The cleanup timeout indicates the hardware was slow to acknowledge
the clear of IMM_RES_VALID, not that the command exchange failed.
Log the anomaly at warn level, then write *response and return 0 so
callers receive the valid data. The stuck IMM_RES_VALID bit will be
cleared at the next invocation by the existing bad-state guard,
provided IMM_CMD_BUSY is not also stuck at that point.

Fixes: d8f48fbdfd9a ("soundwire: amd: Add support for AMD Manager driver")
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
---
 drivers/soundwire/amd_manager.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index f2ed0490aa82..579b12946c0c 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -384,9 +384,12 @@ static int amd_sdw_send_cmd_get_resp(struct amd_sdw_manager *amd_manager, u32 lo
 	ret = readl_poll_timeout(amd_manager->mmio + ACP_SW_IMM_CMD_STS, sts,
 				 !(sts & AMD_SDW_IMM_RES_VALID), ACP_DELAY_US, AMD_SDW_TIMEOUT);
 	if (ret) {
-		dev_err(amd_manager->dev, "SDW%x cmd status retry failed\n",
-			amd_manager->instance);
-		return ret;
+		/* Response already latched above; timeout here is non-fatal.
+		 * The residual IMM_RES_VALID bit will be cleared by the bad-state
+		 * guard on the next invocation, provided IMM_CMD_BUSY is not also stuck.
+		 */
+		dev_warn(amd_manager->dev, "SDW%x cmd status retry failed\n",
+			 amd_manager->instance);
 	}
 	*response = ((u64)upper_resp << 32) | lower_resp;
 	return 0;
-- 
2.53.0