[PATCH 1/3] soundwire: cadence: Don't overflow the command FIFOs

Richard Fitzgerald rf at opensource.cirrus.com
Thu Dec 1 14:48:43 CET 2022


The command FIFOs are 8 entries long, so change CDNS_MCP_CMD_LEN to 8.

CDNS_MCP_CMD_LEN was originally 32, which would lead to cdns_xfer_msg()
writing up to 32 commands into the FIFO, so any message longer than 8
commands would fail.

Signed-off-by: Richard Fitzgerald <rf at opensource.cirrus.com>
Fixes: 2f52a5177caa ("soundwire: cdns: Add cadence library")
---
 drivers/soundwire/cadence_master.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index a1de363eba3f..27699f341f2c 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -127,7 +127,8 @@ MODULE_PARM_DESC(cdns_mcp_int_mask, "Cadence MCP IntMask");
 
 #define CDNS_MCP_CMD_BASE			0x80
 #define CDNS_MCP_RESP_BASE			0x80
-#define CDNS_MCP_CMD_LEN			0x20
+/* FIFO can hold 8 commands */
+#define CDNS_MCP_CMD_LEN			8
 #define CDNS_MCP_CMD_WORD_LEN			0x4
 
 #define CDNS_MCP_CMD_SSP_TAG			BIT(31)
-- 
2.30.2



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