@@ -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;
@@ -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
*
@@ -117,7 +123,12 @@ 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;
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> --- Changes since v1: - Make response_buf large enough for the maximum IP config of 32 plus the mysterious extra 2. - If RX_FIFO_AVAIL is too big trim it to the size of response_buf instead of CDNS_MCP_CMD_LEN. --- drivers/soundwire/cadence_master.c | 7 +++++++ drivers/soundwire/cadence_master.h | 13 ++++++++++++- 2 files changed, 19 insertions(+), 1 deletion(-)