From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
The Cadence IP can be configured in two different ways to deal with CMD_IGNORED replies to broadcast commands. The CMD_ACCEPT bitfield controls whether the command is discarded or if the IP proceeds with the change (typically a bank switch or clock stop command).
The existing code seems to be inconsistent: a) For some historical reason, we set this CMD_ACCEPT bitfield during the initialization, but we don't during a resume from a clock-stoppped state. b) In addition, the loop used in the clock-stop sequence is quite racy, it's possible that a device has lost sync but it's still tagged as ATTACHED. c) If somehow a Device loses sync and is unable to ack a broadcast command, we do not have an error handling mechanism anyways. The IP should go ahead and let the Device regain sync at a later time.
Make sure the CMD_ACCEPT bit is always set.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Guennadi Liakhovetski guennadi.liakhovetski@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/cadence_master.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-)
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 192dac10f0c2..25950422b085 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1428,20 +1428,6 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) } }
- /* - * This CMD_ACCEPT should be used when there are no devices - * attached on the link when entering clock stop mode. If this is - * not set and there is a broadcast write then the command ignored - * will be treated as a failure - */ - if (!slave_present) - cdns_updatel(cdns, CDNS_MCP_CONTROL, - CDNS_MCP_CONTROL_CMD_ACCEPT, - CDNS_MCP_CONTROL_CMD_ACCEPT); - else - cdns_updatel(cdns, CDNS_MCP_CONTROL, - CDNS_MCP_CONTROL_CMD_ACCEPT, 0); - /* commit changes */ ret = cdns_config_update(cdns); if (ret < 0) { @@ -1508,11 +1494,8 @@ int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset) cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_BLOCK_WAKEUP, 0);
- /* - * clear CMD_ACCEPT so that the command ignored - * will be treated as a failure during a broadcast write - */ - cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, 0); + cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, + CDNS_MCP_CONTROL_CMD_ACCEPT);
if (!bus_reset) {