Commit fbbc73a2 authored by Simon Trimmer's avatar Simon Trimmer Committed by Vinod Koul
Browse files

soundwire: cadence: fix updating slave status when a bus has multiple peripherals 



The cadence IP explicitly reports slave status changes with bits for
each possible change. The function cdns_update_slave_status() attempts
to translate this into the current status of each of the slaves.

However when there are multiple peripherals on a bus any slave that did
not have a status change when the work function ran would not have it's
status updated - the array is initialised to a value that equates to
UNATTACHED and this can cause spurious reports that slaves had dropped
off the bus.

In the case where a slave has no status change or has multiple status
changes the value from the last PING command is used.

Signed-off-by: default avatarSimon Trimmer <simont@opensource.cirrus.com>
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/20220914160248.1047627-2-rf@opensource.cirrus.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 279e46bc

drivers/soundwire/cadence_master.c

+25 −32
Original line number Diff line number Diff line
@@ -782,6 +782,7 @@ static int cdns_update_slave_status(struct sdw_cdns *cdns, 
	enum sdw_slave_status status[SDW_MAX_DEVICES + 1];

	bool is_slave = false;

	u32 mask;

	u32 val;

	int i, set_status;



	memset(status, 0, sizeof(status));
@@ -789,12 +790,12 @@ static int cdns_update_slave_status(struct sdw_cdns *cdns, 
	for (i = 0; i <= SDW_MAX_DEVICES; i++) {

		mask = (slave_intstat >> (i * CDNS_MCP_SLAVE_STATUS_NUM)) &

			CDNS_MCP_SLAVE_STATUS_BITS;

		if (!mask)

			continue;



		is_slave = true;

		set_status = 0;



		if (mask) {

			is_slave = true;



			if (mask & CDNS_MCP_SLAVE_INTSTAT_RESERVED) {

				status[i] = SDW_SLAVE_RESERVED;

				set_status++;
@@ -814,16 +815,13 @@ static int cdns_update_slave_status(struct sdw_cdns *cdns, 
				status[i] = SDW_SLAVE_UNATTACHED;

				set_status++;

			}

		}



		/* first check if Slave reported multiple status */

		if (set_status > 1) {

			u32 val;



			dev_warn_ratelimited(cdns->dev,

					     "Slave %d reported multiple Status: %d\n",

					     i, mask);



			/* check latest status extracted from PING commands */

		/*

		 * check that there was a single reported Slave status and when

		 * there is not use the latest status extracted from PING commands

		 */

		if (set_status != 1) {

			val = cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);

			val >>= (i * 2);
@@ -842,11 +840,6 @@ static int cdns_update_slave_status(struct sdw_cdns *cdns, 
				status[i] = SDW_SLAVE_RESERVED;

				break;

			}



			dev_warn_ratelimited(cdns->dev,

					     "Slave %d status updated to %d\n",

					     i, status[i]);



		}

	}