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| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2021-05-11 04:52:47 +0200 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2021-05-11 14:20:33 +0200 |
| commit | 36eee232df7b41dce5a26e4da2d083f6a6b0f476 (patch) | |
| tree | 35069ed490084bf29dbf0e949cffc5f121b434b0 /drivers/soundwire/cadence_master.c | |
| parent | soundwire: bus: add missing \n in dynamic debug (diff) | |
| download | linux-36eee232df7b41dce5a26e4da2d083f6a6b0f476.tar.xz linux-36eee232df7b41dce5a26e4da2d083f6a6b0f476.zip | |
soundwire: cadence_master: always set CMD_ACCEPT
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>
Link: https://lore.kernel.org/r/20210511025247.25339-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire/cadence_master.c')
| -rw-r--r-- | drivers/soundwire/cadence_master.c | 21 |
1 files 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) { |