diff options
Diffstat (limited to 'sound/core/pcm_native.c')
| -rw-r--r-- | sound/core/pcm_native.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 1c53d93e68f2..0d1834310531 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3388,12 +3388,23 @@ static bool pcm_status_mmap_allowed(struct snd_pcm_file *pcm_file) { if (pcm_file->no_compat_mmap) return false; - /* Disallow the status/control mmap when SYNC_APPLPTR flag is set; + /* 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. + */ + if (pcm_file->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 14) && + (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_SYNC_APPLPTR)) + return false; + return true; +} + +static bool pcm_control_mmap_allowed(struct snd_pcm_file *pcm_file) +{ + if (pcm_file->no_compat_mmap) + 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. - * In theory, it should be enough to disallow only PCM control mmap, - * but since the current alsa-lib implementation requires both status - * and control mmaps always paired, we have to disable both of them. */ if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_SYNC_APPLPTR) return false; @@ -3405,6 +3416,7 @@ static bool pcm_status_mmap_allowed(struct snd_pcm_file *pcm_file) * don't support mmap for status and control records. */ #define pcm_status_mmap_allowed(pcm_file) false +#define pcm_control_mmap_allowed(pcm_file) false static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file, struct vm_area_struct *area) @@ -3593,7 +3605,7 @@ static int snd_pcm_mmap(struct file *file, struct vm_area_struct *area) return -ENXIO; return snd_pcm_mmap_status(substream, file, area); case SNDRV_PCM_MMAP_OFFSET_CONTROL: - if (!pcm_status_mmap_allowed(pcm_file)) + if (!pcm_control_mmap_allowed(pcm_file)) return -ENXIO; return snd_pcm_mmap_control(substream, file, area); default: |