ALSA: line6: Add LINE6_CAP_IN_NEEDS_OUT, a void playback stream during capture

E.g. POD X3 seems to require playback data to be sent to it to generate
capture data. Otherwise the device stalls and doesn't send any more capture
data until it's reset.

Signed-off-by: Andrej Krutak <dev@andree.sk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/line6/capture.c b/sound/usb/line6/capture.c
index 0228cb4bdfcff522b34ff2df2d1013f2bf9970c1..7c812565f90db03f5c11fbcf3f92854b0eb3e772 100644 (file)
--- a/sound/usb/line6/capture.c
+++ b/sound/usb/line6/capture.c
@@ -232,6 +232,8 @@ static int snd_line6_capture_open(struct snd_pcm_substream *substream)
        if (err < 0)
                return err;
 
+       line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);
+
        runtime->hw = line6pcm->properties->capture_hw;
        return 0;
 }
@@ -239,6 +241,9 @@ static int snd_line6_capture_open(struct snd_pcm_substream *substream)
 /* close capture callback */
 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
 {
+       struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+
+       line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
        return 0;
 }
 

diff --git a/sound/usb/line6/driver.h b/sound/usb/line6/driver.h
index 2d3213912d4cc82e9e74c17a2c87e5d5cb1cd945..0bcab38ac10db70053d6f76d694737e933f944f5 100644 (file)
--- a/sound/usb/line6/driver.h
+++ b/sound/usb/line6/driver.h
@@ -100,8 +100,10 @@ enum {
        LINE6_CAP_CONTROL =     1 << 0,
        /* device supports PCM input/output via USB */
        LINE6_CAP_PCM =         1 << 1,
-       /* device support hardware monitoring */
+       /* device supports hardware monitoring */
        LINE6_CAP_HWMON =       1 << 2,
+       /* device requires output data when input is read */
+       LINE6_CAP_IN_NEEDS_OUT = 1 << 3,
 };
 
 /*

diff --git a/sound/usb/line6/pcm.c b/sound/usb/line6/pcm.c
index a5a44309bc9dbaefda20a688f82a4a146650c60d..fab53f58d4471c171d427a42e5e3d23d03846be7 100644 (file)
--- a/sound/usb/line6/pcm.c
+++ b/sound/usb/line6/pcm.c
@@ -52,7 +52,7 @@ static int snd_line6_impulse_volume_put(struct snd_kcontrol *kcontrol,
 
        line6pcm->impulse_volume = value;
        if (value > 0) {
-               err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE);
+               err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE, true);
                if (err < 0) {
                        line6pcm->impulse_volume = 0;
                        return err;
@@ -242,6 +242,14 @@ int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
                switch (cmd) {
                case SNDRV_PCM_TRIGGER_START:
                case SNDRV_PCM_TRIGGER_RESUME:
+                       if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
+                               (line6pcm->line6->properties->capabilities &
+                                       LINE6_CAP_IN_NEEDS_OUT)) {
+                               err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
+                                                LINE6_STREAM_CAPTURE_HELPER);
+                               if (err < 0)
+                                       return err;
+                       }
                        err = line6_stream_start(line6pcm, s->stream,
                                                 LINE6_STREAM_PCM);
                        if (err < 0)
@@ -250,6 +258,12 @@ int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
 
                case SNDRV_PCM_TRIGGER_STOP:
                case SNDRV_PCM_TRIGGER_SUSPEND:
+                       if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
+                               (line6pcm->line6->properties->capabilities &
+                                       LINE6_CAP_IN_NEEDS_OUT)) {
+                               line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
+                                         LINE6_STREAM_CAPTURE_HELPER);
+                       }
                        line6_stream_stop(line6pcm, s->stream,
                                          LINE6_STREAM_PCM);
                        break;
@@ -283,14 +297,15 @@ snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
        return pstr->pos_done;
 }
 
-/* Acquire and start duplex streams:
+/* Acquire and optionally start duplex streams:
  * type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
  */
-int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type)
+int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
 {
        struct line6_pcm_stream *pstr;
        int ret = 0, dir;
 
+       /* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
        mutex_lock(&line6pcm->state_mutex);
        for (dir = 0; dir < 2; dir++) {
                pstr = get_stream(line6pcm, dir);
@@ -300,10 +315,12 @@ int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type)
                if (!pstr->running)
                        line6_wait_clear_audio_urbs(line6pcm, pstr);
        }
-       for (dir = 0; dir < 2; dir++) {
-               ret = line6_stream_start(line6pcm, dir, type);
-               if (ret < 0)
-                       goto error;
+       if (start) {
+               for (dir = 0; dir < 2; dir++) {
+                       ret = line6_stream_start(line6pcm, dir, type);
+                       if (ret < 0)
+                               goto error;
+               }
        }
  error:
        mutex_unlock(&line6pcm->state_mutex);

diff --git a/sound/usb/line6/pcm.h b/sound/usb/line6/pcm.h
index 67fda315aa892ac833bdbfd70392e6dc9504bce1..bb0c9cbf2a785c5ae7e937ed78f2475563918364 100644 (file)
--- a/sound/usb/line6/pcm.h
+++ b/sound/usb/line6/pcm.h
@@ -73,6 +73,7 @@ enum {
        LINE6_STREAM_PCM,
        LINE6_STREAM_MONITOR,
        LINE6_STREAM_IMPULSE,
+       LINE6_STREAM_CAPTURE_HELPER,
 };
 
 /* misc bit flags for PCM operation */
@@ -191,7 +192,8 @@ extern int snd_line6_hw_params(struct snd_pcm_substream *substream,
 extern int snd_line6_hw_free(struct snd_pcm_substream *substream);
 extern snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream);
 extern void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm);
-extern int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type);
+extern int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type,
+                              bool start);
 extern void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type);
 
 #endif

diff --git a/sound/usb/line6/toneport.c b/sound/usb/line6/toneport.c
index da76e030eefc357e77e3b5194aa7ff48ac01835a..8e22f430d70072293f9ffabad8bbea6e6834f038 100644 (file)
--- a/sound/usb/line6/toneport.c
+++ b/sound/usb/line6/toneport.c
@@ -177,7 +177,7 @@ static int snd_toneport_monitor_put(struct snd_kcontrol *kcontrol,
        line6pcm->volume_monitor = ucontrol->value.integer.value[0];
 
        if (line6pcm->volume_monitor > 0) {
-               err = line6_pcm_acquire(line6pcm, LINE6_STREAM_MONITOR);
+               err = line6_pcm_acquire(line6pcm, LINE6_STREAM_MONITOR, true);
                if (err < 0) {
                        line6pcm->volume_monitor = 0;
                        line6_pcm_release(line6pcm, LINE6_STREAM_MONITOR);
@@ -246,7 +246,7 @@ static void toneport_start_pcm(unsigned long arg)
        struct usb_line6_toneport *toneport = (struct usb_line6_toneport *)arg;
        struct usb_line6 *line6 = &toneport->line6;
 
-       line6_pcm_acquire(line6->line6pcm, LINE6_STREAM_MONITOR);
+       line6_pcm_acquire(line6->line6pcm, LINE6_STREAM_MONITOR, true);
 }
 
 /* control definition */