From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> The stream management currently flags an 'inconsistent state' error when a change is requested multiple times. This was added on purpose to identify programming mistakes. In hindsight, there was no real reason to fail if the logic at the ASoC-DPCM level invokes the same callback multiple times. It's perfectly acceptable to just return and not flag an error when there is nothing to do. The main concern with the state management is to trap errors such as trying to enable a stream that was not prepared first. This patch suggests allowing the stream functions to be idempotent, i.e. they can be called multiple times. Note that the prepare case was already handling multiple calls, this was added in commit c32464c9393d ("soundwire: stream: only prepare stream when it is configured.") Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx> Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> --- drivers/soundwire/stream.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c index ccf3c99dd579..f273459b2023 100644 --- a/drivers/soundwire/stream.c +++ b/drivers/soundwire/stream.c @@ -1505,6 +1505,11 @@ int sdw_enable_stream(struct sdw_stream_runtime *stream) sdw_acquire_bus_lock(stream); + if (stream->state == SDW_STREAM_ENABLED) { + ret = 0; + goto state_err; + } + if (stream->state != SDW_STREAM_PREPARED && stream->state != SDW_STREAM_DISABLED) { pr_err("%s: %s: inconsistent state state %d\n", @@ -1588,6 +1593,11 @@ int sdw_disable_stream(struct sdw_stream_runtime *stream) sdw_acquire_bus_lock(stream); + if (stream->state == SDW_STREAM_DISABLED) { + ret = 0; + goto state_err; + } + if (stream->state != SDW_STREAM_ENABLED) { pr_err("%s: %s: inconsistent state state %d\n", __func__, stream->name, stream->state); @@ -1663,6 +1673,11 @@ int sdw_deprepare_stream(struct sdw_stream_runtime *stream) sdw_acquire_bus_lock(stream); + if (stream->state == SDW_STREAM_DEPREPARED) { + ret = 0; + goto state_err; + } + if (stream->state != SDW_STREAM_PREPARED && stream->state != SDW_STREAM_DISABLED) { pr_err("%s: %s: inconsistent state state %d\n", -- 2.17.1