The soc_compr_copy callback is currently broken. Since the changes to move the compr_ops over to the component the return value is not correctly propagated, always returning zero on success rather than the number of bytes copied. This causes user-space to stall continuously reading as it does not believe it has received any data.
Furthermore, the changes to move the compr_ops over to the component iterate through the list of components and will call the copy callback for any that have compressed ops. There isn't currently any consensus on the mechanism to combine the results of multiple copy callbacks.
To fix this issue for now halt searching the component list when we locate a copy callback and return the result of that single callback. Additional work should probably be done to look at the other ops, tidy things up, and work out if we want to support multiple components on a single compressed, but this is the only fix required to get things working again.
Fixes: 9e7e3738ab0e ("ASoC: snd_soc_component_driver has snd_compr_ops") Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com ---
Ok here is the simpler fix that should make it much easier to either sneak this into 4.15 or at least apply it to stable.
Going to do a little more thinking on the full patch before I send again that need to really wrap my head around what the intentions are with trying to enable multiple components to furfil the same role. If anyone has any thoughts on use cases etc. for this please do send them on :-)
Thanks, Charles
sound/soc/soc-compress.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c index 81232f4ab614b..7973f92cd40f5 100644 --- a/sound/soc/soc-compress.c +++ b/sound/soc/soc-compress.c @@ -944,7 +944,7 @@ static int soc_compr_copy(struct snd_compr_stream *cstream, struct snd_soc_platform *platform = rtd->platform; struct snd_soc_component *component; struct snd_soc_rtdcom_list *rtdcom; - int ret = 0, __ret; + int ret = 0;
mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
@@ -965,10 +965,10 @@ static int soc_compr_copy(struct snd_compr_stream *cstream, !component->driver->compr_ops->copy) continue;
- __ret = component->driver->compr_ops->copy(cstream, buf, count); - if (__ret < 0) - ret = __ret; + ret = component->driver->compr_ops->copy(cstream, buf, count); + break; } + err: mutex_unlock(&rtd->pcm_mutex); return ret;