[v7,29/33] ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status
Commit Message
Add a kcontrol to the platform sound card to fetch the current offload
status. This can allow for userspace to ensure/check which USB SND
resources are actually busy versus having to attempt opening the USB SND
devices, which will result in an error if offloading is active.
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
sound/soc/qcom/qdsp6/q6usb.c | 104 ++++++++++++++++++++++++++++++++++-
1 file changed, 101 insertions(+), 3 deletions(-)
Comments
On Thu, Sep 21, 2023 at 02:48:39PM -0700, Wesley Cheng wrote:
> Add a kcontrol to the platform sound card to fetch the current offload
> status. This can allow for userspace to ensure/check which USB SND
> resources are actually busy versus having to attempt opening the USB SND
> devices, which will result in an error if offloading is active.
> +static int q6usb_prepare(struct snd_pcm_substream *substream,
> + struct snd_soc_dai *dai)
> +{
> + struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
> +
> + mutex_lock(&data->mutex);
> + data->status[data->sel_card_idx].running = true;
> + mutex_unlock(&data->mutex);
These updates of running should really have a snd_ctl_notify() so that
UIs can know to update when the value changes while they're open.
> +static int q6usb_mixer_get_offload_status(struct snd_kcontrol *kcontrol,
> + struct snd_ctl_elem_value *ucontrol)
> +{
> + running = q6usb_find_running(data);
> + if (running < 0) {
> + card_idx = -1;
> + pcm_idx = -1;
> + } else {
> + card_idx = running;
> + pcm_idx = data->status[running].pcm_index;
> + }
> +
> + ucontrol->value.integer.value[0] = card_idx;
> + ucontrol->value.integer.value[1] = pcm_idx;
This feels a bit messy but I'm not sure what we'd do that's better so
unless someone else has better ideas let's go with this. Possibly we
should standardise this as a new control type for joining cards up so at
least if there's further needs for this we can use the same solution?
Hi Mark,
On 9/27/2023 8:02 AM, Mark Brown wrote:
> On Thu, Sep 21, 2023 at 02:48:39PM -0700, Wesley Cheng wrote:
>
>> Add a kcontrol to the platform sound card to fetch the current offload
>> status. This can allow for userspace to ensure/check which USB SND
>> resources are actually busy versus having to attempt opening the USB SND
>> devices, which will result in an error if offloading is active.
>
>> +static int q6usb_prepare(struct snd_pcm_substream *substream,
>> + struct snd_soc_dai *dai)
>> +{
>> + struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
>> +
>> + mutex_lock(&data->mutex);
>> + data->status[data->sel_card_idx].running = true;
>> + mutex_unlock(&data->mutex);
>
> These updates of running should really have a snd_ctl_notify() so that
> UIs can know to update when the value changes while they're open.
>
Sure, me review some of the APIs again and add the notify call where
necessary.
>> +static int q6usb_mixer_get_offload_status(struct snd_kcontrol *kcontrol,
>> + struct snd_ctl_elem_value *ucontrol)
>> +{
>
>> + running = q6usb_find_running(data);
>> + if (running < 0) {
>> + card_idx = -1;
>> + pcm_idx = -1;
>> + } else {
>> + card_idx = running;
>> + pcm_idx = data->status[running].pcm_index;
>> + }
>> +
>> + ucontrol->value.integer.value[0] = card_idx;
>> + ucontrol->value.integer.value[1] = pcm_idx;
>
> This feels a bit messy but I'm not sure what we'd do that's better so
> unless someone else has better ideas let's go with this. Possibly we
> should standardise this as a new control type for joining cards up so at
> least if there's further needs for this we can use the same solution?
I'm all ears for any suggestions from other users :). I think its a bit
difficult to tell since this is the first iteration of adding this
feature. Pierre gave me some great feedback from the
userspace/application level, and tried my best to accommodate for those
requirements since it would be the main entity interacting with these
controls.
Thanks
Wesley Cheng
@@ -30,6 +30,8 @@ struct q6usb_status {
unsigned int num_pcm;
unsigned int chip_index;
unsigned int pcm_index;
+ bool prepared;
+ bool running;
};
struct q6usb_port_data {
@@ -52,6 +54,17 @@ static const struct snd_soc_dapm_route q6usb_dapm_routes[] = {
{"USB Playback", NULL, "USB_RX_BE"},
};
+static int q6usb_find_running(struct q6usb_port_data *data)
+{
+ int i;
+
+ for (i = 0; i < SNDRV_CARDS; i++) {
+ if (data->status[i].running)
+ return i;
+ }
+ return -ENODEV;
+}
+
static int q6usb_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *dai)
@@ -81,14 +94,40 @@ static int q6usb_hw_params(struct snd_pcm_substream *substream,
goto out;
data->status[data->sel_card_idx].pcm_index = data->sel_pcm_idx;
+ data->status[data->sel_card_idx].prepared = true;
out:
mutex_unlock(&data->mutex);
return ret;
}
+static int q6usb_prepare(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+
+ mutex_lock(&data->mutex);
+ data->status[data->sel_card_idx].running = true;
+ mutex_unlock(&data->mutex);
+
+ return 0;
+}
+
+static void q6usb_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+
+ mutex_lock(&data->mutex);
+ data->status[data->sel_card_idx].running = false;
+ data->status[data->sel_card_idx].prepared = false;
+ mutex_unlock(&data->mutex);
+}
+
static const struct snd_soc_dai_ops q6usb_ops = {
.hw_params = q6usb_hw_params,
+ .prepare = q6usb_prepare,
+ .shutdown = q6usb_shutdown,
};
static struct snd_soc_dai_driver q6usb_be_dais[] = {
@@ -148,10 +187,15 @@ static int q6usb_put_offload_dev(struct snd_kcontrol *kcontrol,
int pcmidx;
int cardidx;
+ mutex_lock(&data->mutex);
+
+ /* Don't allow changes to the offloading devices if session is busy */
+ if (data->sel_card_idx >= 0 && data->status[data->sel_card_idx].prepared)
+ goto out;
+
cardidx = ucontrol->value.integer.value[0];
pcmidx = ucontrol->value.integer.value[1];
- mutex_lock(&data->mutex);
if ((cardidx >= 0 && test_bit(cardidx, &data->available_card_slot))) {
data->sel_card_idx = cardidx;
changed = 1;
@@ -162,6 +206,8 @@ static int q6usb_put_offload_dev(struct snd_kcontrol *kcontrol,
data->idx_valid = true;
changed = 1;
}
+
+out:
mutex_unlock(&data->mutex);
return changed;
@@ -187,11 +233,59 @@ static const struct snd_kcontrol_new q6usb_offload_dev_ctrl = {
.put = q6usb_put_offload_dev,
};
+static int q6usb_mixer_get_offload_status(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+ struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+ int running;
+ int card_idx;
+ int pcm_idx;
+
+ running = q6usb_find_running(data);
+ if (running < 0) {
+ card_idx = -1;
+ pcm_idx = -1;
+ } else {
+ card_idx = running;
+ pcm_idx = data->status[running].pcm_index;
+ }
+
+ ucontrol->value.integer.value[0] = card_idx;
+ ucontrol->value.integer.value[1] = pcm_idx;
+ return 0;
+}
+
+static int q6usb_offload_ctl_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 2;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = SNDRV_CARDS;
+
+ return 0;
+}
+
+static const struct snd_kcontrol_new q6usb_offload_control = {
+ .iface = SNDRV_CTL_ELEM_IFACE_CARD,
+ .access = SNDRV_CTL_ELEM_ACCESS_READ,
+ .name = "Q6USB offload status",
+ .info = q6usb_offload_ctl_info,
+ .get = q6usb_mixer_get_offload_status,
+ .put = NULL,
+};
+
/* Build a mixer control for a UAC connector control (jack-detect) */
static void q6usb_connector_control_init(struct snd_soc_component *component)
{
int ret;
+ ret = snd_ctl_add(component->card->snd_card,
+ snd_ctl_new1(&q6usb_offload_control, component));
+ if (ret < 0)
+ return;
+
ret = snd_ctl_add(component->card->snd_card,
snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
if (ret < 0)
@@ -229,8 +323,12 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
mutex_lock(&data->mutex);
if (connected) {
- /* We only track the latest USB headset plugged in */
- if (!data->idx_valid || data->sel_card_idx < 0)
+ /*
+ * Update the latest USB headset plugged in, if session is
+ * idle.
+ */
+ if ((!data->idx_valid || data->sel_card_idx < 0) &&
+ !data->status[data->sel_card_idx].prepared)
data->sel_card_idx = sdev->card_idx;
set_bit(sdev->card_idx, &data->available_card_slot);