From: Richard Fitzgerald Date: Fri, 2 Dec 2022 16:18:10 +0000 (+0000) Subject: soundwire: cadence: Don't overflow the command FIFOs X-Git-Tag: v6.6.7~3424^2~16 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7cbfee2e2e40d2be54196362a845a3ea0a3f877d;p=platform%2Fkernel%2Flinux-starfive.git soundwire: cadence: Don't overflow the command FIFOs 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 Reviewed-by: Pierre-Louis Bossart Fixes: 2f52a5177caa ("soundwire: cdns: Add cadence library") Link: https://lore.kernel.org/r/20221202161812.4186897-2-rf@opensource.cirrus.com Signed-off-by: Vinod Koul --- diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index a1de363..27699f3 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)