Hi Pierre,
On 8/30/2024 2:55 AM, Pierre-Louis Bossart wrote:
>
> On 8/29/24 21:41, Wesley Cheng wrote:
>> Add proper checks and updates to the USB substream once receiving a USB QMI
>> stream enable request. If the substream is already in use from the non
>> offload path, reject the stream enable request. In addition, update the
>> USB substream opened parameter when enabling the offload path, so the
>> non offload path can be blocked.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>> sound/usb/qcom/qc_audio_offload.c | 15 ++++++++++++++-
>> 1 file changed, 14 insertions(+), 1 deletion(-)
>>
>> diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
>> index e9f2fd6bbb41..0bd533f539e4 100644
>> --- a/sound/usb/qcom/qc_audio_offload.c
>> +++ b/sound/usb/qcom/qc_audio_offload.c
>> @@ -1482,12 +1482,17 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
>> goto response;
>> }
>>
>> + mutex_lock(&chip->mutex);
>> if (req_msg->enable) {
>> - if (info_idx < 0 || chip->system_suspend) {
>> + if (info_idx < 0 || chip->system_suspend || subs->opened) {
>> ret = -EBUSY;
>> + mutex_unlock(&chip->mutex);
>> +
>> goto response;
>> }
>> + subs->opened = 1;
>> }
>> + mutex_unlock(&chip->mutex);
>>
>> if (req_msg->service_interval_valid) {
>> ret = get_data_interval_from_si(subs,
>> @@ -1509,6 +1514,11 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
>> if (!ret)
>> ret = prepare_qmi_response(subs, req_msg, &resp,
>> info_idx);
>> + if (ret < 0) {
>> + mutex_lock(&chip->mutex);
>> + subs->opened = 0;
>> + mutex_unlock(&chip->mutex);
>> + }
>> } else {
>> info = &uadev[pcm_card_num].info[info_idx];
>> if (info->data_ep_pipe) {
>> @@ -1532,6 +1542,9 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
>> }
>>
>> disable_audio_stream(subs);
>> + mutex_lock(&chip->mutex);
>> + subs->opened = 0;
>> + mutex_unlock(&chip->mutex);
>> }
>>
>
> This sounds ok but I wonder why all this needs to be done in
> Qualcomm-specific layers instead of soc-usb?
>
This is to prevent conflicts within the non-offload/legacy USB SND path and the USB SND offload vendor driver. Don't think we need to involve anything with ASoC in these checks.
Thanks
Wesley Cheng