From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> We sometimes see COMMAND_IGNORED responses during the clock stop sequence. It turns out we already have information if devices are present on a link, so we should only prepare those when they are attached. In addition, even when COMMAND_IGNORED are received, we should still proceed with the clock stop. The device will not be prepared but that's not a problem. The only case where the clock stop will fail is if the Cadence IP reports an error (including a timeout), or if the devices throw a COMMAND_FAILED response. BugLink: https://github.com/thesofproject/linux/issues/2621 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx> Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx> Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> --- drivers/soundwire/cadence_master.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index d05442e646a3..57c59a33ce61 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1450,10 +1450,12 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) } /* Prepare slaves for clock stop */ - ret = sdw_bus_prep_clk_stop(&cdns->bus); - if (ret < 0) { - dev_err(cdns->dev, "prepare clock stop failed %d", ret); - return ret; + if (slave_present) { + ret = sdw_bus_prep_clk_stop(&cdns->bus); + if (ret < 0 && ret != -ENODATA) { + dev_err(cdns->dev, "prepare clock stop failed %d\n", ret); + return ret; + } } /* -- 2.17.1
