Commit 0df63e44 authored by Takashi Iwai's avatar Takashi Iwai Committed by Jaroslav Kysela
Browse files

[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: default avatarTakashi Iwai <tiwai@suse.de>
parent f001c3ac

include/sound/asound.h

+1 −1
Original line number Diff line number Diff line
@@ -137,7 +137,7 @@ enum { 
 *                                                                           *

 *****************************************************************************/



#define SNDRV_PCM_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 7)

#define SNDRV_PCM_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 8)



typedef unsigned long snd_pcm_uframes_t;

typedef signed long snd_pcm_sframes_t;

include/sound/pcm.h

+3 −2
Original line number Diff line number Diff line
@@ -368,7 +368,8 @@ struct snd_pcm_substream { 
	struct snd_pcm_group *group;		/* pointer to current group */

	/* -- assigned files -- */

	void *file;

	struct file *ffile;

	int ref_count;

	unsigned int f_flags;

	void (*pcm_release)(struct snd_pcm_substream *);

#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)

	/* -- OSS things -- */
@@ -387,7 +388,7 @@ struct snd_pcm_substream { 
	unsigned int hw_opened: 1;

};



#define SUBSTREAM_BUSY(substream) ((substream)->file != NULL)

#define SUBSTREAM_BUSY(substream) ((substream)->ref_count > 0)





struct snd_pcm_str {

sound/core/oss/pcm_oss.c

+10 −7
Original line number Diff line number Diff line
@@ -1331,7 +1331,7 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha 
				if (runtime->oss.period_ptr == 0 ||

				    runtime->oss.period_ptr == runtime->oss.buffer_used)

					runtime->oss.buffer_used = 0;

				else if ((substream->ffile->f_flags & O_NONBLOCK) != 0)

				else if ((substream->f_flags & O_NONBLOCK) != 0)

					return xfer > 0 ? xfer : -EAGAIN;

			}

		} else {
@@ -1344,7 +1344,7 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha 
			buf += tmp;

			bytes -= tmp;

			xfer += tmp;

			if ((substream->ffile->f_flags & O_NONBLOCK) != 0 &&

			if ((substream->f_flags & O_NONBLOCK) != 0 &&

			    tmp != runtime->oss.period_bytes)

				break;

		}
@@ -1582,10 +1582,10 @@ static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file) 
		 * finish sync: drain the buffer

		 */

	      __direct:

		saved_f_flags = substream->ffile->f_flags;

		substream->ffile->f_flags &= ~O_NONBLOCK;

		saved_f_flags = substream->f_flags;

		substream->f_flags &= ~O_NONBLOCK;

		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);

		substream->ffile->f_flags = saved_f_flags;

		substream->f_flags = saved_f_flags;

		if (err < 0)

			return err;

		runtime->oss.prepare = 1;
@@ -2164,9 +2164,9 @@ static void snd_pcm_oss_init_substream(struct snd_pcm_substream *substream, 
	substream->oss.oss = 1;

	substream->oss.setup = *setup;

	if (setup->nonblock)

		substream->ffile->f_flags |= O_NONBLOCK;

		substream->f_flags |= O_NONBLOCK;

	else if (setup->block)

		substream->ffile->f_flags &= ~O_NONBLOCK;

		substream->f_flags &= ~O_NONBLOCK;

	runtime = substream->runtime;

	runtime->oss.params = 1;

	runtime->oss.trigger = 1;
@@ -2223,6 +2223,7 @@ static int snd_pcm_oss_open_file(struct file *file, 
	    (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX))

		f_mode = FMODE_WRITE;



	file->f_flags &= ~O_APPEND;

	for (idx = 0; idx < 2; idx++) {

		if (setup[idx].disable)

			continue;
@@ -2540,6 +2541,7 @@ static ssize_t snd_pcm_oss_read(struct file *file, char __user *buf, size_t coun 
	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];

	if (substream == NULL)

		return -ENXIO;

	substream->f_flags = file->f_flags & O_NONBLOCK;

#ifndef OSS_DEBUG

	return snd_pcm_oss_read1(substream, buf, count);

#else
@@ -2561,6 +2563,7 @@ static ssize_t snd_pcm_oss_write(struct file *file, const char __user *buf, size 
	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];

	if (substream == NULL)

		return -ENXIO;

	substream->f_flags = file->f_flags & O_NONBLOCK;

	result = snd_pcm_oss_write1(substream, buf, count);

#ifdef OSS_DEBUG

	printk("pcm_oss: write %li bytes (wrote %li bytes)\n", (long)count, (long)result);

sound/core/pcm.c

+23 −2
Original line number Diff line number Diff line
@@ -829,6 +829,26 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, 
		return -EINVAL;

	}



	if (file->f_flags & O_APPEND) {

		if (prefer_subdevice < 0) {

			if (pstr->substream_count > 1)

				return -EINVAL; /* must be unique */

			substream = pstr->substream;

		} else {

			for (substream = pstr->substream; substream;

			     substream = substream->next)

				if (substream->number == prefer_subdevice)

					break;

		}

		if (! substream)

			return -ENODEV;

		if (! SUBSTREAM_BUSY(substream))

			return -EBADFD;

		substream->ref_count++;

		*rsubstream = substream;

		return 0;

	}



	if (prefer_subdevice >= 0) {

		for (substream = pstr->substream; substream; substream = substream->next)

			if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
@@ -873,7 +893,8 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, 


	substream->runtime = runtime;

	substream->private_data = pcm->private_data;

	substream->ffile = file;

	substream->ref_count = 1;

	substream->f_flags = file->f_flags;

	pstr->substream_opened++;

	*rsubstream = substream;

	return 0;
@@ -882,7 +903,7 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, 
void snd_pcm_detach_substream(struct snd_pcm_substream *substream)

{

	struct snd_pcm_runtime *runtime;

	substream->file = NULL;



	runtime = substream->runtime;

	snd_assert(runtime != NULL, return);

	if (runtime->private_free != NULL)

sound/core/pcm_compat.c

+2 −2
Original line number Diff line number Diff line
@@ -497,9 +497,9 @@ static long snd_pcm_ioctl_compat(struct file *file, unsigned int cmd, unsigned l 
	case SNDRV_PCM_IOCTL_LINK:

	case SNDRV_PCM_IOCTL_UNLINK:

		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)

			return snd_pcm_playback_ioctl1(substream, cmd, argp);

			return snd_pcm_playback_ioctl1(file, substream, cmd, argp);

		else

			return snd_pcm_capture_ioctl1(substream, cmd, argp);

			return snd_pcm_capture_ioctl1(file, substream, cmd, argp);

	case SNDRV_PCM_IOCTL_HW_REFINE32:

		return snd_pcm_ioctl_hw_params_compat(substream, 1, argp);

	case SNDRV_PCM_IOCTL_HW_PARAMS32: