2024-06-11 00:03:54

by Wesley Cheng

Subject: [PATCH v23 17/32] ALSA: usb-audio: Do not allow USB offload path if PCM device is in use

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 <[email protected]>
---
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 eda16d6df0d7..648b97aeae1d 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -1460,12 +1460,17 @@ 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,
@@ -1487,6 +1492,11 @@ 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) {
@@ -1510,6 +1520,9 @@ 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);
}

response:

2024-06-12 14:59:16

by Amadeusz Sławiński

Subject: Re: [PATCH v23 17/32] ALSA: usb-audio: Do not allow USB offload path if PCM device is in use

On 6/11/2024 1:57 AM, 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 <[email protected]>
> ---
> sound/usb/qcom/qc_audio_offload.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)

Patch title is missing qcom part and it clearly touches QCOM code.
ALSA: usb-audio: qcom: