2023-10-17 20:02:32

by Wesley Cheng

Subject: [PATCH v9 27/34] ALSA: usb-audio: qcom: Populate PCM and USB chip information

Currently, only the index to the USB SND card array is passed to the USB
backend. Pass through more information, specifically the USB SND card
number and the number of PCM devices available. This allows for the DPCM
backend to determine what USB resources are available during situations,
such as USB audio offloading.

Signed-off-by: Wesley Cheng <[email protected]>
---
sound/usb/qcom/qc_audio_offload.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
index bd6b84f72c74..ae74098b41f5 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -173,6 +173,21 @@ enum usb_qmi_audio_format {
USB_QMI_PCM_FORMAT_U32_BE,
};

+static int usb_qmi_get_pcm_num(struct snd_usb_audio *chip, int direction)
+{
+ struct snd_usb_substream *subs = NULL;
+ struct snd_usb_stream *as;
+ int count = 0;
+
+ list_for_each_entry(as, &chip->pcm_list, list) {
+ subs = &as->substream[direction];
+ if (subs->ep_num)
+ count++;
+ }
+
+ return count;
+}
+
static enum usb_qmi_audio_device_speed_enum_v01
get_speed_info(enum usb_device_speed udev_speed)
{
@@ -1592,6 +1607,8 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)

sdev->card_idx = chip->card->number;
sdev->chip_idx = chip->index;
+ sdev->num_playback = usb_qmi_get_pcm_num(chip, 0);
+ sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
uadev[chip->card->number].sdev = sdev;

uaudio_qdev->last_card_num = chip->card->number;
@@ -1706,10 +1723,8 @@ static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
mutex_unlock(&chip->mutex);

atomic_dec(&uaudio_qdev->qdev_in_use);
- if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
- snd_soc_usb_disconnect(usb_get_usb_backend(udev));
+ if (!atomic_read(&uaudio_qdev->qdev_in_use))
qc_usb_audio_cleanup_qmi_dev();
- }
mutex_unlock(&qdev_mutex);
}

2023-10-17 23:24:08

by Pierre-Louis Bossart

Subject: Re: [PATCH v9 27/34] ALSA: usb-audio: qcom: Populate PCM and USB chip information

On 10/17/23 15:01, Wesley Cheng wrote:
> Currently, only the index to the USB SND card array is passed to the USB
> backend. Pass through more information, specifically the USB SND card
> number and the number of PCM devices available. This allows for the DPCM
> backend to determine what USB resources are available during situations,
> such as USB audio offloading.
>
> Signed-off-by: Wesley Cheng <[email protected]>
> ---
> sound/usb/qcom/qc_audio_offload.c | 21 ++++++++++++++++++---
> 1 file changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
> index bd6b84f72c74..ae74098b41f5 100644
> --- a/sound/usb/qcom/qc_audio_offload.c
> +++ b/sound/usb/qcom/qc_audio_offload.c
> @@ -173,6 +173,21 @@ enum usb_qmi_audio_format {
> USB_QMI_PCM_FORMAT_U32_BE,
> };
>
> +static int usb_qmi_get_pcm_num(struct snd_usb_audio *chip, int direction)
> +{
> + struct snd_usb_substream *subs = NULL;
> + struct snd_usb_stream *as;
> + int count = 0;
> +
> + list_for_each_entry(as, &chip->pcm_list, list) {
> + subs = &as->substream[direction];
> + if (subs->ep_num)
> + count++;
> + }
> +
> + return count;
> +}
> +
> static enum usb_qmi_audio_device_speed_enum_v01
> get_speed_info(enum usb_device_speed udev_speed)
> {
> @@ -1592,6 +1607,8 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
>
> sdev->card_idx = chip->card->number;
> sdev->chip_idx = chip->index;
> + sdev->num_playback = usb_qmi_get_pcm_num(chip, 0);
> + sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
> uadev[chip->card->number].sdev = sdev;
>
> uaudio_qdev->last_card_num = chip->card->number;
> @@ -1706,10 +1723,8 @@ static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
> mutex_unlock(&chip->mutex);
>
> atomic_dec(&uaudio_qdev->qdev_in_use);
> - if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
> - snd_soc_usb_disconnect(usb_get_usb_backend(udev));

this also feels like a patch split issue, removing this
snd_soc_usb_disconnect() has nothing to do with the "populate PCM and
USB chip information" ?

> + if (!atomic_read(&uaudio_qdev->qdev_in_use))
> qc_usb_audio_cleanup_qmi_dev();
> - }
> mutex_unlock(&qdev_mutex);
> }
>

2023-10-19 00:59:58

by Wesley Cheng

Subject: Re: [PATCH v9 27/34] ALSA: usb-audio: qcom: Populate PCM and USB chip information

Hi Pierre,

On 10/17/2023 3:41 PM, Pierre-Louis Bossart wrote:
>
>
> On 10/17/23 15:01, Wesley Cheng wrote:
>> Currently, only the index to the USB SND card array is passed to the USB
>> backend. Pass through more information, specifically the USB SND card
>> number and the number of PCM devices available. This allows for the DPCM
>> backend to determine what USB resources are available during situations,
>> such as USB audio offloading.
>>
>> Signed-off-by: Wesley Cheng <[email protected]>
>> ---
>> sound/usb/qcom/qc_audio_offload.c | 21 ++++++++++++++++++---
>> 1 file changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
>> index bd6b84f72c74..ae74098b41f5 100644
>> --- a/sound/usb/qcom/qc_audio_offload.c
>> +++ b/sound/usb/qcom/qc_audio_offload.c
>> @@ -173,6 +173,21 @@ enum usb_qmi_audio_format {
>> USB_QMI_PCM_FORMAT_U32_BE,
>> };
>>
>> +static int usb_qmi_get_pcm_num(struct snd_usb_audio *chip, int direction)
>> +{
>> + struct snd_usb_substream *subs = NULL;
>> + struct snd_usb_stream *as;
>> + int count = 0;
>> +
>> + list_for_each_entry(as, &chip->pcm_list, list) {
>> + subs = &as->substream[direction];
>> + if (subs->ep_num)
>> + count++;
>> + }
>> +
>> + return count;
>> +}
>> +
>> static enum usb_qmi_audio_device_speed_enum_v01
>> get_speed_info(enum usb_device_speed udev_speed)
>> {
>> @@ -1592,6 +1607,8 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
>>
>> sdev->card_idx = chip->card->number;
>> sdev->chip_idx = chip->index;
>> + sdev->num_playback = usb_qmi_get_pcm_num(chip, 0);
>> + sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
>> uadev[chip->card->number].sdev = sdev;
>>
>> uaudio_qdev->last_card_num = chip->card->number;
>> @@ -1706,10 +1723,8 @@ static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
>> mutex_unlock(&chip->mutex);
>>
>> atomic_dec(&uaudio_qdev->qdev_in_use);
>> - if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
>> - snd_soc_usb_disconnect(usb_get_usb_backend(udev));
>
> this also feels like a patch split issue, removing this
> snd_soc_usb_disconnect() has nothing to do with the "populate PCM and
> USB chip information" ?
>

Will fix this.

Thanks
Wesley Cheng