diff options
Diffstat (limited to 'sound/core/pcm_native.c')
| -rw-r--r-- | sound/core/pcm_native.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index dc9fa312fadd..d233cb3b41d8 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3621,6 +3621,12 @@ static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file static bool pcm_status_mmap_allowed(struct snd_pcm_file *pcm_file) { + /* If drivers require the explicit sync (typically for non-coherent + * pages), we have to disable the mmap of status and control data + * to enforce the control via SYNC_PTR ioctl. + */ + if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_EXPLICIT_SYNC) + return false; /* See pcm_control_mmap_allowed() below. * Since older alsa-lib requires both status and control mmaps to be * coupled, we have to disable the status mmap for old alsa-lib, too. @@ -3635,6 +3641,9 @@ static bool pcm_control_mmap_allowed(struct snd_pcm_file *pcm_file) { if (pcm_file->no_compat_mmap) return false; + /* see above */ + if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_EXPLICIT_SYNC) + return false; /* Disallow the control mmap when SYNC_APPLPTR flag is set; * it enforces the user-space to fall back to snd_pcm_sync_ptr(), * thus it effectively assures the manual update of appl_ptr. |