From: Timo Wischer <twischer@xxxxxxxxxxxxxx>
Without this fix the application pointer would be reseted
whenever an application opens a device with SND_PCM_APPEND.
This would result in an Xrun if the device is already opened and
in running state and the appl_ptr is use.
Signed-off-by: Timo Wischer <twischer@xxxxxxxxxxxxxx>
diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c
index b93926c..65b198c 100644
--- a/src/pcm/pcm_hw.c
+++ b/src/pcm/pcm_hw.c
@@ -1004,16 +1004,28 @@ static int map_status_and_control_data(snd_pcm_t *pcm, bool force_fallback)
hw->sync_ptr = NULL;
}
- /* Initialize the data. */
- hw->mmap_control->appl_ptr = 0;
- hw->mmap_control->avail_min = 1;
+ /* do not initialize in case of append and keep the values from the
+ * kernel
+ */
+ if (!(pcm->mode & SND_PCM_APPEND)) {
+ /* Initialize the data. */
+ hw->mmap_control->appl_ptr = 0;
+ hw->mmap_control->avail_min = 1;
+ }
snd_pcm_set_hw_ptr(pcm, &hw->mmap_status->hw_ptr, hw->fd,
SNDRV_PCM_MMAP_OFFSET_STATUS +
offsetof(struct snd_pcm_mmap_status, hw_ptr));
snd_pcm_set_appl_ptr(pcm, &hw->mmap_control->appl_ptr, hw->fd,
SNDRV_PCM_MMAP_OFFSET_CONTROL);
if (hw->mmap_control_fallbacked) {
- err = sync_ptr1(hw, 0);
+ unsigned int flags;
+ /* read appl_ptr and avail_min from kernel when device opened
+ * with SND_PCM_APPEND flag
+ */
+ if (pcm->mode & SND_PCM_APPEND)
+ flags = SNDRV_PCM_SYNC_PTR_APPL |
+ SNDRV_PCM_SYNC_PTR_AVAIL_MIN;
+ err = sync_ptr1(hw, flags);
if (err < 0)
return err;
}
@@ -1539,6 +1551,8 @@ int snd_pcm_hw_open_fd(snd_pcm_t **pcmp, const char *name, int fd,
mode |= SND_PCM_NONBLOCK;
if (fmode & O_ASYNC)
mode |= SND_PCM_ASYNC;
+ if (fmode & O_APPEND)
+ mode |= SND_PCM_APPEND;
if (ioctl(fd, SNDRV_PCM_IOCTL_PVERSION, &ver) < 0) {
ret = -errno;
--
2.7.4
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