Commit 10f69f9e authored by Takashi Iwai's avatar Takashi Iwai Committed by Jaroslav Kysela
Browse files

[ALSA] pcm-oss - Add bugg-yptr option 



Documentation,ALSA<-OSS emulation
Added 'buggy-ptr' proc option to switch the behavior of GETOPTR ioctl.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent f3283853

Documentation/sound/alsa/ALSA-Configuration.txt

+2 −0
Original line number Diff line number Diff line
@@ -1592,6 +1592,8 @@ Proc interfaces (/proc/asound) 
	  - whole-frag  write only whole fragments (optimization affecting

			playback only)

	  - no-silence  do not fill silence ahead to avoid clicks

	  - buggy-ptr	Returns the whitespace blocks in GETOPTR ioctl

			instead of filled blocks



  Example: echo "x11amp 128 16384" > /proc/asound/card0/pcm0p/oss

           echo "squake 0 0 disable" > /proc/asound/card0/pcm0c/oss

include/sound/pcm_oss.h

+2 −1
Original line number Diff line number Diff line
@@ -32,7 +32,8 @@ struct _snd_pcm_oss_setup { 
		     block:1,

		     nonblock:1,

		     partialfrag:1,

		     nosilence:1;

		     nosilence:1,

		     buggyptr:1;

	unsigned int periods;

	unsigned int period_size;

	snd_pcm_oss_setup_t *next;

sound/core/oss/pcm_oss.c

+7 −1
Original line number Diff line number Diff line
@@ -1543,7 +1543,11 @@ static int snd_pcm_oss_get_ptr(snd_pcm_oss_file_t *pcm_oss_file, int stream, str 
	} else {

		delay = snd_pcm_oss_bytes(substream, delay);

		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {

			snd_pcm_oss_setup_t *setup = substream->oss.setup;

			if (setup && setup->buggyptr)

				info.blocks = (runtime->oss.buffer_bytes - delay - fixup) / runtime->oss.period_bytes;

			else

				info.blocks = (delay + fixup) / runtime->oss.period_bytes;

			info.bytes = (runtime->oss.bytes - delay) & INT_MAX;

		} else {

			delay += fixup;
@@ -2350,6 +2354,8 @@ static void snd_pcm_oss_proc_write(snd_info_entry_t *entry, 
				template.partialfrag = 1;

			} else if (!strcmp(str, "no-silence")) {

				template.nosilence = 1;

			} else if (!strcmp(str, "buggy-ptr")) {

				template.buggyptr = 1;

			}

		} while (*str);

		if (setup == NULL) {