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| author | Richard Fitzgerald <rf@opensource.cirrus.com> | 2022-12-02 16:18:11 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 13:55:40 +0100 |
| commit | 51eb90be9fd8cfb4d037a06bc55eb28b1aa0f406 (patch) | |
| tree | e21ff274e23fb499936a1d88a7ea91b4fd9db2ef | |
| parent | 425cd1b471245fecd9630f65ee93e21ff6b152f0 (diff) | |
| download | linux-51eb90be9fd8cfb4d037a06bc55eb28b1aa0f406.tar.gz | |
soundwire: cadence: Remove wasted space in response_buf
[ Upstream commit 827c32d0df4bbe0d1c47d79f6a5eabfe9ac75216 ] 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 <rf@opensource.cirrus.com> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20221202161812.4186897-3-rf@opensource.cirrus.com Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/soundwire/cadence_master.c | 7 | ||||
| -rw-r--r-- | drivers/soundwire/cadence_master.h | 13 |
2 files changed, 19 insertions, 1 deletions
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index b65cdf2a7593..6cd9db19758c 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; diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index ca9e805bab88..51e6ecc027cb 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -8,6 +8,12 @@ #define SDW_CADENCE_GSYNC_KHZ 4 /* 4 kHz */ #define SDW_CADENCE_GSYNC_HZ (SDW_CADENCE_GSYNC_KHZ * 1000) +/* + * The Cadence IP supports up to 32 entries in the FIFO, though implementations + * can configure the IP to have a smaller FIFO. + */ +#define CDNS_MCP_IP_MAX_CMD_LEN 32 + /** * struct sdw_cdns_pdi: PDI (Physical Data Interface) instance * @@ -114,7 +120,12 @@ struct sdw_cdns { struct sdw_bus bus; unsigned int instance; - u32 response_buf[0x80]; + /* + * The datasheet says the RX FIFO AVAIL can be 2 entries more + * than the FIFO capacity, so allow for this. + */ + u32 response_buf[CDNS_MCP_IP_MAX_CMD_LEN + 2]; + struct completion tx_complete; struct sdw_defer *defer; |