On 12/1/22 07:48, Richard Fitzgerald wrote:
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.
The change is correct for all instances of SoundWire on Intel platforms. That said, maybe we should capture that the Cadence IP can handle 4/8/16/32 entries - this is a hardware configuration option.
We should also mention that so far we have not sent multiple commands so far so the code is only broken when grouping commands.
Reviewed-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
Signed-off-by: Richard Fitzgerald rf@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)