From 093a5463aeecc8a8d13bac233652cf6532d53dd7 Mon Sep 17 00:00:00 2001 From: Richard Fitzgerald Date: Fri, 16 Sep 2022 11:35:05 +0100 Subject: [PATCH] soundwire: cadence: Don't overwrite msg->buf during write commands [ Upstream commit ba05b39d265bdd16913f7684600d9d41e2796745 ] The buf passed in struct sdw_msg must only be written for a READ, in that case the RDATA part of the response is the data value of the register. For a write command there is no RDATA, and buf should be assumed to be const and unmodifable. The original caller should not expect its data buffer to be corrupted by an sdw_nwrite(). Signed-off-by: Richard Fitzgerald Reviewed-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20220916103505.1562210-1-rf@opensource.cirrus.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/soundwire/cadence_master.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 4fcc3ba..18d2f9b 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -545,9 +545,12 @@ cdns_fill_msg_resp(struct sdw_cdns *cdns, return SDW_CMD_IGNORED; } - /* fill response */ - for (i = 0; i < count; i++) - msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA, cdns->response_buf[i]); + if (msg->flags == SDW_MSG_FLAG_READ) { + /* fill response */ + for (i = 0; i < count; i++) + msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA, + cdns->response_buf[i]); + } return SDW_CMD_OK; } -- 2.7.4