[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: Takashi Iwai <tiwai@suse.de>
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index a7fc75f..57e82a5 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -1592,6 +1592,8 @@
- 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
diff --git a/include/sound/pcm_oss.h b/include/sound/pcm_oss.h
index 5187285..0b67c9d 100644
--- a/include/sound/pcm_oss.h
+++ b/include/sound/pcm_oss.h
@@ -32,7 +32,8 @@
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;
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 1e60639..a038fd8 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1543,7 +1543,11 @@
} else {
delay = snd_pcm_oss_bytes(substream, delay);
if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
- info.blocks = (runtime->oss.buffer_bytes - delay - fixup) / runtime->oss.period_bytes;
+ 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 @@
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) {