This is a note to let you know that I've just added the patch titled
soundwire: cadence: fix ACK/NAK handling
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
soundwire-cadence-fix-ack-nak-handling.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6fb5681d796e094e448d98d3070c35a9be0c00e2
Author: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Date: Fri Jan 15 13:37:37 2021 +0800
soundwire: cadence: fix ACK/NAK handling
[ Upstream commit db9d9f944f95e7f3aa60ac00cbd502415152c421 ]
The existing code reports a NAK only when ACK=0
This is not aligned with the SoundWire 1.x specifications.
Table 32 in the SoundWire 1.2 specification shows that a Device shall
not set NAK=1 if ACK=1. But Table 33 shows the Combined Response
may very well be NAK=1/ACK=1, e.g. if another Device than the one
addressed reports a parity error.
NAK=1 signals a 'Command_Aborted', regardless of the ACK bit value.
Move the tests for NAK so that the NAK=1/ACK=1 combination is properly
detected according to the specification.
Fixes: 956baa1992f9a ('soundwire: cdns: Add sdw_master_ops and IO transfer support')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210115053738.22630-5-yung-chuan.liao@xxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 9fa55164354a2..580660599f461 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -484,10 +484,10 @@ cdns_fill_msg_resp(struct sdw_cdns *cdns,
if (!(cdns->response_buf[i] & CDNS_MCP_RESP_ACK)) {
no_ack = 1;
dev_dbg_ratelimited(cdns->dev, "Msg Ack not received\n");
- if (cdns->response_buf[i] & CDNS_MCP_RESP_NACK) {
- nack = 1;
- dev_err_ratelimited(cdns->dev, "Msg NACK received\n");
- }
+ }
+ if (cdns->response_buf[i] & CDNS_MCP_RESP_NACK) {
+ nack = 1;
+ dev_err_ratelimited(cdns->dev, "Msg NACK received\n");
}
}
