[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 (file)
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -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

diff --git a/include/sound/pcm_oss.h b/include/sound/pcm_oss.h
index 5187285..0b67c9d 100644 (file)
--- a/include/sound/pcm_oss.h
+++ b/include/sound/pcm_oss.h
@@ -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;

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 1e60639..a038fd8 100644 (file)
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -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) {
-                       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 @@ 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) {