From 0df63e44c3e315ec0fe427ae62558231864108bd Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 28 Apr 2006 15:13:41 +0200 Subject: [ALSA] Add O_APPEND flag support to PCM Added O_APPEND flag support to PCM to enable shared substreams among multiple processes. This mechanism is used by dmix and dsnoop plugins. Signed-off-by: Takashi Iwai --- sound/core/pcm_native.c | 81 +++++++++++++++++++++++++++++++++---------------- 1 file changed, 55 insertions(+), 26 deletions(-) (limited to 'sound/core/pcm_native.c') diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 7b5729c4b21..36d6765618a 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1284,13 +1284,16 @@ static int snd_pcm_reset(struct snd_pcm_substream *substream) /* * prepare ioctl */ -static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream, int state) +/* we use the second argument for updating f_flags */ +static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream, + int f_flags) { struct snd_pcm_runtime *runtime = substream->runtime; if (runtime->status->state == SNDRV_PCM_STATE_OPEN) return -EBADFD; if (snd_pcm_running(substream)) return -EBUSY; + substream->f_flags = f_flags; return 0; } @@ -1319,17 +1322,26 @@ static struct action_ops snd_pcm_action_prepare = { /** * snd_pcm_prepare * @substream: the PCM substream instance + * @file: file to refer f_flags * * Prepare the PCM substream to be triggerable. */ -static int snd_pcm_prepare(struct snd_pcm_substream *substream) +static int snd_pcm_prepare(struct snd_pcm_substream *substream, + struct file *file) { int res; struct snd_card *card = substream->pcm->card; + int f_flags; + + if (file) + f_flags = file->f_flags; + else + f_flags = substream->f_flags; snd_power_lock(card); if ((res = snd_power_wait(card, SNDRV_CTL_POWER_D0)) >= 0) - res = snd_pcm_action_nonatomic(&snd_pcm_action_prepare, substream, 0); + res = snd_pcm_action_nonatomic(&snd_pcm_action_prepare, + substream, f_flags); snd_power_unlock(card); return res; } @@ -1340,7 +1352,7 @@ static int snd_pcm_prepare(struct snd_pcm_substream *substream) static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream, int state) { - if (substream->ffile->f_flags & O_NONBLOCK) + if (substream->f_flags & O_NONBLOCK) return -EAGAIN; substream->runtime->trigger_master = substream; return 0; @@ -2015,6 +2027,10 @@ static void pcm_release_private(struct snd_pcm_substream *substream) void snd_pcm_release_substream(struct snd_pcm_substream *substream) { + substream->ref_count--; + if (substream->ref_count > 0) + return; + snd_pcm_drop(substream); if (substream->hw_opened) { if (substream->ops->hw_free != NULL) @@ -2041,6 +2057,11 @@ int snd_pcm_open_substream(struct snd_pcm *pcm, int stream, err = snd_pcm_attach_substream(pcm, stream, file, &substream); if (err < 0) return err; + if (substream->ref_count > 1) { + *rsubstream = substream; + return 0; + } + substream->no_mmap_ctrl = 0; err = snd_pcm_hw_constraints_init(substream); if (err < 0) { @@ -2086,17 +2107,20 @@ static int snd_pcm_open_file(struct file *file, if (err < 0) return err; - pcm_file = kzalloc(sizeof(*pcm_file), GFP_KERNEL); - if (pcm_file == NULL) { - snd_pcm_release_substream(substream); - return -ENOMEM; + if (substream->ref_count > 1) + pcm_file = substream->file; + else { + pcm_file = kzalloc(sizeof(*pcm_file), GFP_KERNEL); + if (pcm_file == NULL) { + snd_pcm_release_substream(substream); + return -ENOMEM; + } + str = substream->pstr; + substream->file = pcm_file; + substream->pcm_release = pcm_release_private; + pcm_file->substream = substream; + snd_pcm_add_file(str, pcm_file); } - str = substream->pstr; - substream->file = pcm_file; - substream->pcm_release = pcm_release_private; - pcm_file->substream = substream; - snd_pcm_add_file(str, pcm_file); - file->private_data = pcm_file; *rpcm_file = pcm_file; return 0; @@ -2506,7 +2530,8 @@ static int snd_pcm_sync_ptr(struct snd_pcm_substream *substream, return 0; } -static int snd_pcm_common_ioctl1(struct snd_pcm_substream *substream, +static int snd_pcm_common_ioctl1(struct file *file, + struct snd_pcm_substream *substream, unsigned int cmd, void __user *arg) { snd_assert(substream != NULL, return -ENXIO); @@ -2531,7 +2556,7 @@ static int snd_pcm_common_ioctl1(struct snd_pcm_substream *substream, case SNDRV_PCM_IOCTL_CHANNEL_INFO: return snd_pcm_channel_info_user(substream, arg); case SNDRV_PCM_IOCTL_PREPARE: - return snd_pcm_prepare(substream); + return snd_pcm_prepare(substream, file); case SNDRV_PCM_IOCTL_RESET: return snd_pcm_reset(substream); case SNDRV_PCM_IOCTL_START: @@ -2573,7 +2598,8 @@ static int snd_pcm_common_ioctl1(struct snd_pcm_substream *substream, return -ENOTTY; } -static int snd_pcm_playback_ioctl1(struct snd_pcm_substream *substream, +static int snd_pcm_playback_ioctl1(struct file *file, + struct snd_pcm_substream *substream, unsigned int cmd, void __user *arg) { snd_assert(substream != NULL, return -ENXIO); @@ -2649,10 +2675,11 @@ static int snd_pcm_playback_ioctl1(struct snd_pcm_substream *substream, return result < 0 ? result : 0; } } - return snd_pcm_common_ioctl1(substream, cmd, arg); + return snd_pcm_common_ioctl1(file, substream, cmd, arg); } -static int snd_pcm_capture_ioctl1(struct snd_pcm_substream *substream, +static int snd_pcm_capture_ioctl1(struct file *file, + struct snd_pcm_substream *substream, unsigned int cmd, void __user *arg) { snd_assert(substream != NULL, return -ENXIO); @@ -2728,7 +2755,7 @@ static int snd_pcm_capture_ioctl1(struct snd_pcm_substream *substream, return result < 0 ? result : 0; } } - return snd_pcm_common_ioctl1(substream, cmd, arg); + return snd_pcm_common_ioctl1(file, substream, cmd, arg); } static long snd_pcm_playback_ioctl(struct file *file, unsigned int cmd, @@ -2741,7 +2768,8 @@ static long snd_pcm_playback_ioctl(struct file *file, unsigned int cmd, if (((cmd >> 8) & 0xff) != 'A') return -ENOTTY; - return snd_pcm_playback_ioctl1(pcm_file->substream, cmd, (void __user *)arg); + return snd_pcm_playback_ioctl1(file, pcm_file->substream, cmd, + (void __user *)arg); } static long snd_pcm_capture_ioctl(struct file *file, unsigned int cmd, @@ -2754,7 +2782,8 @@ static long snd_pcm_capture_ioctl(struct file *file, unsigned int cmd, if (((cmd >> 8) & 0xff) != 'A') return -ENOTTY; - return snd_pcm_capture_ioctl1(pcm_file->substream, cmd, (void __user *)arg); + return snd_pcm_capture_ioctl1(file, pcm_file->substream, cmd, + (void __user *)arg); } int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream, @@ -2766,12 +2795,12 @@ int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream, fs = snd_enter_user(); switch (substream->stream) { case SNDRV_PCM_STREAM_PLAYBACK: - result = snd_pcm_playback_ioctl1(substream, - cmd, (void __user *)arg); + result = snd_pcm_playback_ioctl1(NULL, substream, cmd, + (void __user *)arg); break; case SNDRV_PCM_STREAM_CAPTURE: - result = snd_pcm_capture_ioctl1(substream, - cmd, (void __user *)arg); + result = snd_pcm_capture_ioctl1(NULL, substream, cmd, + (void __user *)arg); break; default: result = -EINVAL; -- cgit v1.2.3