From 18f50b8304084084a87a31f51dd6357fac2c5efd Mon Sep 17 00:00:00 2001 From: Richard Fitzgerald Date: Fri, 2 Dec 2022 16:18:10 +0000 Subject: [PATCH] soundwire: cadence: Don't overflow the command FIFOs [ Upstream commit 7cbfee2e2e40d2be54196362a845a3ea0a3f877d ] 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 Signed-off-by: Sasha Levin --- 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 18d2f9b3e2010..0339e6df6eb78 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