The command FIFOs in the Cadence IP can be configured during design up to 32 entries, and the code in cadence_master.c was assuming the full 32-entry FIFO. But all current Intel implementations use an 8-entry FIFO.
Up to now the longest message used was 6 entries so this wasn't causing any problem. But future Cirrus Logic codecs have downloadable firmware or tuning blobs. It is more efficient for the codec driver to issue long transfers that can take advantage of any queuing in the Soundwire controller and avoid the overhead of repeatedly writing the page registers.
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com Reviewed-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Fixes: 2f52a5177caa ("soundwire: cdns: Add cadence library") --- Changes since v1: Commit description rewritten. No code change. --- 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)