staging: line6: fixed ALSA/PCM interaction

The PCM subsystem in the Line6 driver is mainly used for PCM playback and
capture by ALSA, but also has other tasks, most notably providing a
low-latency software monitor for devices which don't support hardware
monitoring (e.g., the TonePort series). This patch makes ALSA "play nicely"
with the other components, i.e., prevents it from resetting the isochronous
USB transfer while other PCM tasks (software monitoring) are running.

Signed-off-by: Markus Grabner <grabner@icg.tugraz.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/line6/capture.c b/drivers/staging/line6/capture.c
index 8f59ff3e7a175f12797ad0296e32dc01027afefc..127f95247749f0827d223d0605f4c5bbea0d6f93 100644 (file)
--- a/drivers/staging/line6/capture.c
+++ b/drivers/staging/line6/capture.c
@@ -193,6 +193,31 @@ void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
        }
 }
 
+int line6_alloc_capture_buffer(struct snd_line6_pcm *line6pcm)
+{
+       /* We may be invoked multiple times in a row so allocate once only */
+       if (line6pcm->buffer_in)
+               return 0;
+
+       line6pcm->buffer_in =
+               kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
+                       line6pcm->max_packet_size, GFP_KERNEL);
+
+       if (!line6pcm->buffer_in) {
+               dev_err(line6pcm->line6->ifcdev,
+                       "cannot malloc capture buffer\n");
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
+void line6_free_capture_buffer(struct snd_line6_pcm *line6pcm)
+{
+       kfree(line6pcm->buffer_in);
+       line6pcm->buffer_in = NULL;
+}
+
 /*
  * Callback for completed capture URB.
  */
@@ -316,16 +341,11 @@ static int snd_line6_capture_hw_params(struct snd_pcm_substream *substream,
        }
        /* -- [FD] end */
 
-       /* We may be invoked multiple times in a row so allocate once only */
-       if (!line6pcm->buffer_in)
-               line6pcm->buffer_in =
-                       kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
-                               line6pcm->max_packet_size, GFP_KERNEL);
+       if ((line6pcm->flags & MASK_CAPTURE) == 0) {
+               ret = line6_alloc_capture_buffer(line6pcm);
 
-       if (!line6pcm->buffer_in) {
-               dev_err(line6pcm->line6->ifcdev,
-                       "cannot malloc capture buffer\n");
-               return -ENOMEM;
+               if (ret < 0)
+                       return ret;
        }
 
        ret = snd_pcm_lib_malloc_pages(substream,
@@ -342,9 +362,11 @@ static int snd_line6_capture_hw_free(struct snd_pcm_substream *substream)
 {
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 
-       line6_unlink_wait_clear_audio_in_urbs(line6pcm);
-       kfree(line6pcm->buffer_in);
-       line6pcm->buffer_in = NULL;
+       if ((line6pcm->flags & MASK_CAPTURE) == 0) {
+               line6_unlink_wait_clear_audio_in_urbs(line6pcm);
+               line6_free_capture_buffer(line6pcm);
+       }
+
        return snd_pcm_lib_free_pages(substream);
 }
 

diff --git a/drivers/staging/line6/capture.h b/drivers/staging/line6/capture.h
index a7509fbbb9545408be75a48a61184ec12457f8d9..366cbaa7c88da134417e57a77a7760d8e273e77a 100644 (file)
--- a/drivers/staging/line6/capture.h
+++ b/drivers/staging/line6/capture.h
@@ -19,11 +19,13 @@
 
 extern struct snd_pcm_ops snd_line6_capture_ops;
 
+extern int line6_alloc_capture_buffer(struct snd_line6_pcm *line6pcm);
 extern void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf,
                               int fsize);
 extern void line6_capture_check_period(struct snd_line6_pcm *line6pcm,
                                       int length);
 extern int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm);
+extern void line6_free_capture_buffer(struct snd_line6_pcm *line6pcm);
 extern int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm);
 extern void line6_unlink_audio_in_urbs(struct snd_line6_pcm *line6pcm);
 extern void line6_unlink_wait_clear_audio_in_urbs(struct snd_line6_pcm

diff --git a/drivers/staging/line6/pcm.c b/drivers/staging/line6/pcm.c
index 68727b2dfb8fbd0d5ffa00cac96a81f8282cd143..37675e66da8189b2cb17c686f183ea267da76d58 100644 (file)
--- a/drivers/staging/line6/pcm.c
+++ b/drivers/staging/line6/pcm.c
@@ -86,17 +86,22 @@ static DEVICE_ATTR(impulse_period, S_IWUSR | S_IRUGO, pcm_get_impulse_period,
 
 #endif
 
+static bool test_flags(unsigned long flags0, unsigned long flags1,
+                      unsigned long mask)
+{
+       return ((flags0 & mask) == 0) && ((flags1 & mask) != 0);
+}
+
 int line6_pcm_start(struct snd_line6_pcm *line6pcm, int channels)
 {
        unsigned long flags_old =
            __sync_fetch_and_or(&line6pcm->flags, channels);
        unsigned long flags_new = flags_old | channels;
        int err = 0;
-
+       
        line6pcm->prev_fbuf = NULL;
 
-       if (((flags_old & MASK_CAPTURE) == 0) &&
-           ((flags_new & MASK_CAPTURE) != 0)) {
+       if (test_flags(flags_old, flags_new, MASK_CAPTURE)) {
                /*
                   Waiting for completion of active URBs in the stop handler is
                   a bug, we therefore report an error if capturing is restarted
@@ -105,34 +110,47 @@ int line6_pcm_start(struct snd_line6_pcm *line6pcm, int channels)
                if (line6pcm->active_urb_in | line6pcm->unlink_urb_in)
                        return -EBUSY;
 
+               if (!(flags_new & MASK_PCM_ALSA_CAPTURE)) {
+                       err = line6_alloc_capture_buffer(line6pcm);
+
+                       if (err < 0)
+                               goto pcm_start_error;
+               }
+
                line6pcm->count_in = 0;
                line6pcm->prev_fsize = 0;
                err = line6_submit_audio_in_all_urbs(line6pcm);
 
-               if (err < 0) {
-                       __sync_fetch_and_and(&line6pcm->flags, ~channels);
-                       return err;
-               }
+               if (err < 0)
+                       goto pcm_start_error;
        }
 
-       if (((flags_old & MASK_PLAYBACK) == 0) &&
-           ((flags_new & MASK_PLAYBACK) != 0)) {
+       if (test_flags(flags_old, flags_new, MASK_PLAYBACK)) {
                /*
                   See comment above regarding PCM restart.
                 */
                if (line6pcm->active_urb_out | line6pcm->unlink_urb_out)
                        return -EBUSY;
 
+               if (!(flags_new & MASK_PCM_ALSA_PLAYBACK)) {
+                       err = line6_alloc_playback_buffer(line6pcm);
+
+                       if (err < 0)
+                               goto pcm_start_error;
+               }
+
                line6pcm->count_out = 0;
                err = line6_submit_audio_out_all_urbs(line6pcm);
 
-               if (err < 0) {
-                       __sync_fetch_and_and(&line6pcm->flags, ~channels);
-                       return err;
-               }
+               if (err < 0)
+                       goto pcm_start_error;
        }
 
        return 0;
+
+pcm_start_error:
+       __sync_fetch_and_and(&line6pcm->flags, ~channels);
+       return err;
 }
 
 int line6_pcm_stop(struct snd_line6_pcm *line6pcm, int channels)
@@ -141,14 +159,18 @@ int line6_pcm_stop(struct snd_line6_pcm *line6pcm, int channels)
            __sync_fetch_and_and(&line6pcm->flags, ~channels);
        unsigned long flags_new = flags_old & ~channels;
 
-       if (((flags_old & MASK_CAPTURE) != 0) &&
-           ((flags_new & MASK_CAPTURE) == 0)) {
+       if (test_flags(flags_new, flags_old, MASK_CAPTURE)) {
                line6_unlink_audio_in_urbs(line6pcm);
+
+               if (!(flags_old & MASK_PCM_ALSA_CAPTURE))
+                       line6_free_capture_buffer(line6pcm);
        }
 
-       if (((flags_old & MASK_PLAYBACK) != 0) &&
-           ((flags_new & MASK_PLAYBACK) == 0)) {
+       if (test_flags(flags_new, flags_old, MASK_PLAYBACK)) {
                line6_unlink_audio_out_urbs(line6pcm);
+
+               if (!(flags_old & MASK_PCM_ALSA_PLAYBACK))
+                       line6_free_playback_buffer(line6pcm);
        }
 
        return 0;
@@ -476,18 +498,21 @@ int snd_line6_prepare(struct snd_pcm_substream *substream)
 
        switch (substream->stream) {
        case SNDRV_PCM_STREAM_PLAYBACK:
-               line6_unlink_wait_clear_audio_out_urbs(line6pcm);
+               if ((line6pcm->flags & MASK_PLAYBACK) == 0)
+                       line6_unlink_wait_clear_audio_out_urbs(line6pcm);
+
                break;
 
        case SNDRV_PCM_STREAM_CAPTURE:
-               line6_unlink_wait_clear_audio_in_urbs(line6pcm);
+               if ((line6pcm->flags & MASK_CAPTURE) == 0)
+                       line6_unlink_wait_clear_audio_in_urbs(line6pcm);
+
                break;
 
        default:
                MISSING_CASE;
        }
 
-
        if (!test_and_set_bit(BIT_PREPARED, &line6pcm->flags)) {
                line6pcm->count_out = 0;
                line6pcm->pos_out = 0;

diff --git a/drivers/staging/line6/playback.c b/drivers/staging/line6/playback.c
index 9a51b92c09485a06234eabe3cdf8c4352ad8740b..4152db2328b7e15ca6ee1ce47021c2c8d2499aa8 100644 (file)
--- a/drivers/staging/line6/playback.c
+++ b/drivers/staging/line6/playback.c
@@ -351,6 +351,31 @@ void line6_unlink_wait_clear_audio_out_urbs(struct snd_line6_pcm *line6pcm)
        wait_clear_audio_out_urbs(line6pcm);
 }
 
+int line6_alloc_playback_buffer(struct snd_line6_pcm *line6pcm)
+{
+       /* We may be invoked multiple times in a row so allocate once only */
+       if (line6pcm->buffer_out)
+               return 0;
+
+       line6pcm->buffer_out =
+               kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
+                       line6pcm->max_packet_size, GFP_KERNEL);
+
+       if (!line6pcm->buffer_out) {
+               dev_err(line6pcm->line6->ifcdev,
+                       "cannot malloc playback buffer\n");
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
+void line6_free_playback_buffer(struct snd_line6_pcm *line6pcm)
+{
+       kfree(line6pcm->buffer_out);
+       line6pcm->buffer_out = NULL;
+}
+
 /*
        Callback for completed playback URB.
 */
@@ -459,16 +484,11 @@ static int snd_line6_playback_hw_params(struct snd_pcm_substream *substream,
        }
        /* -- [FD] end */
 
-       /* We may be invoked multiple times in a row so allocate once only */
-       if (!line6pcm->buffer_out)
-               line6pcm->buffer_out =
-                       kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
-                               line6pcm->max_packet_size, GFP_KERNEL);
+       if ((line6pcm->flags & MASK_PLAYBACK) == 0) {
+               ret = line6_alloc_playback_buffer(line6pcm);
 
-       if (!line6pcm->buffer_out) {
-               dev_err(line6pcm->line6->ifcdev,
-                       "cannot malloc playback buffer\n");
-               return -ENOMEM;
+               if (ret < 0)
+                       return ret;
        }
 
        ret = snd_pcm_lib_malloc_pages(substream,
@@ -485,9 +505,11 @@ static int snd_line6_playback_hw_free(struct snd_pcm_substream *substream)
 {
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 
-       line6_unlink_wait_clear_audio_out_urbs(line6pcm);
-       kfree(line6pcm->buffer_out);
-       line6pcm->buffer_out = NULL;
+       if ((line6pcm->flags & MASK_PLAYBACK) == 0) {
+               line6_unlink_wait_clear_audio_out_urbs(line6pcm);
+               line6_free_playback_buffer(line6pcm);
+       }
+
        return snd_pcm_lib_free_pages(substream);
 }
 

diff --git a/drivers/staging/line6/playback.h b/drivers/staging/line6/playback.h
index f2fc8c0526e313d5d1aede620f2d49bc8e166a55..02487ff245384e26e9d44e32e27362aba089b2d0 100644 (file)
--- a/drivers/staging/line6/playback.h
+++ b/drivers/staging/line6/playback.h
@@ -29,7 +29,9 @@
 
 extern struct snd_pcm_ops snd_line6_playback_ops;
 
+extern int line6_alloc_playback_buffer(struct snd_line6_pcm *line6pcm);
 extern int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm);
+extern void line6_free_playback_buffer(struct snd_line6_pcm *line6pcm);
 extern int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm);
 extern void line6_unlink_audio_out_urbs(struct snd_line6_pcm *line6pcm);
 extern void line6_unlink_wait_clear_audio_out_urbs(struct snd_line6_pcm

diff --git a/drivers/staging/line6/revision.h b/drivers/staging/line6/revision.h
index 350d0dfff8f8d9d09a0ab42ca8e67a3c6ec42eef..b4eee2b73831e2be19fe1ddc1c5d2de6494918a2 100644 (file)
--- a/drivers/staging/line6/revision.h
+++ b/drivers/staging/line6/revision.h
@@ -1,4 +1,4 @@
 #ifndef DRIVER_REVISION
 /* current subversion revision */
-#define DRIVER_REVISION " (revision 690)"
+#define DRIVER_REVISION " (904)"
 #endif