pcm: handle negative values from snd_pcm_mmap_hw_avail

Such negative values can happen when an underrun happens and xrun
detection is disabled. Another situation is if the device updated the
pointer before alsa-lib has a chance to detect the xrun.

The problem is that these negative values could propagate to the
snd_pcm_rewindable return value, where it is specified that negative
returns must be interpreted as error codes and not as negative amount of
samples.

Signed-off-by: Alexander E. Patrakov <patrakov@gmail.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Alexander E. Patrakov 2014-09-14 00:30:15 +06:00 committed by Jaroslav Kysela
parent 9a43dc15b2
commit 78c804fc93
6 changed files with 23 additions and 7 deletions

View file

@ -661,7 +661,7 @@ static int snd_pcm_dmix_pause(snd_pcm_t *pcm ATTRIBUTE_UNUSED, int enable ATTRIB
static snd_pcm_sframes_t snd_pcm_dmix_rewindable(snd_pcm_t *pcm)
{
return snd_pcm_mmap_hw_avail(pcm);
return snd_pcm_mmap_playback_hw_rewindable(pcm);
}
static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)

View file

@ -412,7 +412,7 @@ static int snd_pcm_dshare_pause(snd_pcm_t *pcm ATTRIBUTE_UNUSED, int enable ATTR
static snd_pcm_sframes_t snd_pcm_dshare_rewindable(snd_pcm_t *pcm)
{
return snd_pcm_mmap_playback_hw_avail(pcm);
return snd_pcm_mmap_playback_hw_rewindable(pcm);
}
static snd_pcm_sframes_t snd_pcm_dshare_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
@ -420,8 +420,6 @@ static snd_pcm_sframes_t snd_pcm_dshare_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t
snd_pcm_sframes_t avail;
avail = snd_pcm_dshare_rewindable(pcm);
if (avail < 0)
return 0;
if (frames > (snd_pcm_uframes_t)avail)
frames = avail;
snd_pcm_mmap_appl_backward(pcm, frames);

View file

@ -659,7 +659,7 @@ static int snd_pcm_hw_pause(snd_pcm_t *pcm, int enable)
static snd_pcm_sframes_t snd_pcm_hw_rewindable(snd_pcm_t *pcm)
{
return snd_pcm_mmap_hw_avail(pcm);
return snd_pcm_mmap_hw_rewindable(pcm);
}
static snd_pcm_sframes_t snd_pcm_hw_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)

View file

@ -503,7 +503,7 @@ static int snd_pcm_ioplug_pause(snd_pcm_t *pcm, int enable)
static snd_pcm_sframes_t snd_pcm_ioplug_rewindable(snd_pcm_t *pcm)
{
return snd_pcm_mmap_hw_avail(pcm);
return snd_pcm_mmap_hw_rewindable(pcm);
}
static snd_pcm_sframes_t snd_pcm_ioplug_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)

View file

@ -464,6 +464,24 @@ static inline snd_pcm_sframes_t snd_pcm_mmap_hw_avail(snd_pcm_t *pcm)
return pcm->buffer_size - snd_pcm_mmap_avail(pcm);
}
static inline snd_pcm_sframes_t snd_pcm_mmap_playback_hw_rewindable(snd_pcm_t *pcm)
{
snd_pcm_sframes_t ret = snd_pcm_mmap_playback_hw_avail(pcm);
return (ret >= 0) ? ret : 0;
}
static inline snd_pcm_sframes_t snd_pcm_mmap_capture_hw_rewindable(snd_pcm_t *pcm)
{
snd_pcm_sframes_t ret = snd_pcm_mmap_capture_hw_avail(pcm);
return (ret >= 0) ? ret : 0;
}
static inline snd_pcm_uframes_t snd_pcm_mmap_hw_rewindable(snd_pcm_t *pcm)
{
snd_pcm_sframes_t ret = snd_pcm_mmap_hw_avail(pcm);
return (ret >= 0) ? ret : 0;
}
static inline const snd_pcm_channel_area_t *snd_pcm_mmap_areas(snd_pcm_t *pcm)
{
if (pcm->stopped_areas &&

View file

@ -198,7 +198,7 @@ static int snd_pcm_plugin_reset(snd_pcm_t *pcm)
static snd_pcm_sframes_t snd_pcm_plugin_rewindable(snd_pcm_t *pcm)
{
return snd_pcm_mmap_hw_avail(pcm);
return snd_pcm_mmap_hw_rewindable(pcm);
}
snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)