From 827c32d0df4bbe0d1c47d79f6a5eabfe9ac75216 Mon Sep 17 00:00:00 2001 From: Richard Fitzgerald Date: Fri, 2 Dec 2022 16:18:11 +0000 Subject: soundwire: cadence: Remove wasted space in response_buf The response_buf was declared much larger (128 entries) than the number of responses that could ever be written into it. The Cadence IP is configurable up to a maximum of 32 entries, and the datasheet says that RX_FIFO_AVAIL can be 2 larger than this. So allow up to 34 responses. Also add checking in cdns_read_response() to prevent overflowing reponse_buf if RX_FIFO_AVAIL contains an unexpectedly large number. Signed-off-by: Richard Fitzgerald Reviewed-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20221202161812.4186897-3-rf@opensource.cirrus.com Signed-off-by: Vinod Koul --- drivers/soundwire/cadence_master.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/soundwire/cadence_master.c') diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 27699f341f2c..a6635f7f350e 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -774,8 +774,15 @@ static void cdns_read_response(struct sdw_cdns *cdns) u32 num_resp, cmd_base; int i; + /* RX_FIFO_AVAIL can be 2 entries more than the FIFO size */ + BUILD_BUG_ON(ARRAY_SIZE(cdns->response_buf) < CDNS_MCP_CMD_LEN + 2); + num_resp = cdns_readl(cdns, CDNS_MCP_FIFOSTAT); num_resp &= CDNS_MCP_RX_FIFO_AVAIL; + if (num_resp > ARRAY_SIZE(cdns->response_buf)) { + dev_warn(cdns->dev, "RX AVAIL %d too long\n", num_resp); + num_resp = ARRAY_SIZE(cdns->response_buf); + } cmd_base = CDNS_MCP_CMD_BASE; -- cgit v1.2.3