On 5/3/23 09:41, Krzysztof Kozlowski wrote: > The WCD938x comes with three devices on two Linux drivers: > 1. RX Soundwire device (wcd938x-sdw.c driver), > 2. TX Soundwire device, which is used to access devices via regmap (also > wcd938x-sdw.c driver), > 3. platform device (wcd938x.c driver) - glue and component master, > actually having most of the code using TX Soundwire device regmap. > > When RX and TX Soundwire devices probe, the component master (platform > device) bind tries to write micbias configuration via TX Soundwire > regmap. This might happen before TX Soundwire enumerates, so the regmap > access fails. On Qualcomm SM8550 board with WCD9385: > > qcom-soundwire 6d30000.soundwire-controller: Qualcomm Soundwire controller v2.0.0 Registered > wcd938x_codec audio-codec: bound sdw:0:0217:010d:00:4 (ops wcd938x_sdw_component_ops) > wcd938x_codec audio-codec: bound sdw:0:0217:010d:00:3 (ops wcd938x_sdw_component_ops) > qcom-soundwire 6ad0000.soundwire-controller: swrm_wait_for_wr_fifo_avail err write overflow > > Fix the issue by: > 1. Moving the regmap creation from platform device to TX Soundwire > device. The regmap settings are moved as-is with one difference: > making the wcd938x_regmap_config const. > 2. Using regmap in cache only mode till the actual TX Soundwire device > enumerates and then sync the regmap cache. > > Cc: <stable@xxxxxxxxxxxxxxx> # v3.14+ > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > > --- > > Cc: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> > Cc: Patrick Lai <quic_plai@xxxxxxxxxxx> > Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> > > Changes since v1: > 1. Previous solution touched Soundwire. Rework it according to feedback. > https://lore.kernel.org/all/20230420101617.142225-7-krzysztof.kozlowski@xxxxxxxxxx/ > > Thank you Mark and Pierre-Louis for great hints and valuable feedback! LGTM, this was a very interesting thread to comment on. Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
