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pcm: hw: Keep control data from kernel when SND_PCM_APPEND

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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@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Timo Wischer 2018-03-23 15:27:23 +01:00 • committed by Takashi Iwai
parent 64b8927df3
commit dc4325d8c1
1 changed files with 18 additions and 4 deletions
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22
src/pcm/pcm_hw.c
View file

@ -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;