Commit 87b6bc89 authored by Richard Fitzgerald's avatar Richard Fitzgerald Committed by sanglipeng
Browse files

soundwire: cadence: Remove wasted space in response_buf 

stable inclusion
from stable-v5.10.173
commit e5ca5b71363a0a4902f8968191e8ddf939b5018e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7X0QU

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e5ca5b71363a0a4902f8968191e8ddf939b5018e



--------------------------------

[ Upstream commit 827c32d0 ]

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: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20221202161812.4186897-3-rf@opensource.cirrus.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent 79346b17

drivers/soundwire/cadence_master.c

+7 −0
Original line number Diff line number Diff line
@@ -725,8 +725,15 @@ 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;

drivers/soundwire/cadence_master.h

+12 −1
Original line number Diff line number Diff line
@@ -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

 *
@@ -119,7 +125,12 @@ 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;