ALSA: pcm_lib - cleanup & merge hw_ptr update functions
Do general cleanup in snd_pcm_update_hw_ptr*() routines and merge them.
The main change is hw_ptr_interrupt variable removal to simplify code
logic. This variable can be computed directly from hw_ptr.
Ensure that updated hw_ptr is not lower than previous one (it was possible
with old code in some obscure situations when interrupt was delayed or
the lowlevel driver returns wrong ring buffer position value).
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index d9c9635..255ad91 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -632,6 +632,13 @@
return bytes_to_frames(runtime, (buffer_size * bytes) / runtime->oss.buffer_bytes);
}
+static inline
+snd_pcm_uframes_t get_hw_ptr_period(struct snd_pcm_runtime *runtime)
+{
+ snd_pcm_uframes_t ptr = runtime->status->hw_ptr;
+ return ptr - (ptr % runtime->period_size);
+}
+
/* define extended formats in the recent OSS versions (if any) */
/* linear formats */
#define AFMT_S32_LE 0x00001000
@@ -1102,7 +1109,7 @@
return err;
}
runtime->oss.prepare = 0;
- runtime->oss.prev_hw_ptr_interrupt = 0;
+ runtime->oss.prev_hw_ptr_period = 0;
runtime->oss.period_ptr = 0;
runtime->oss.buffer_used = 0;
@@ -1950,7 +1957,8 @@
return result;
}
-static void snd_pcm_oss_simulate_fill(struct snd_pcm_substream *substream, snd_pcm_uframes_t hw_ptr)
+static void snd_pcm_oss_simulate_fill(struct snd_pcm_substream *substream,
+ snd_pcm_uframes_t hw_ptr)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t appl_ptr;
@@ -1986,7 +1994,8 @@
if (runtime->oss.trigger)
goto _skip1;
if (atomic_read(&psubstream->mmap_count))
- snd_pcm_oss_simulate_fill(psubstream, runtime->hw_ptr_interrupt);
+ snd_pcm_oss_simulate_fill(psubstream,
+ get_hw_ptr_period(runtime));
runtime->oss.trigger = 1;
runtime->start_threshold = 1;
cmd = SNDRV_PCM_IOCTL_START;
@@ -2105,11 +2114,12 @@
info.ptr = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr % runtime->buffer_size);
if (atomic_read(&substream->mmap_count)) {
snd_pcm_sframes_t n;
- n = (delay = runtime->hw_ptr_interrupt) - runtime->oss.prev_hw_ptr_interrupt;
+ delay = get_hw_ptr_period(runtime);
+ n = delay - runtime->oss.prev_hw_ptr_period;
if (n < 0)
n += runtime->boundary;
info.blocks = n / runtime->period_size;
- runtime->oss.prev_hw_ptr_interrupt = delay;
+ runtime->oss.prev_hw_ptr_period = delay;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
snd_pcm_oss_simulate_fill(substream, delay);
info.bytes = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr) & INT_MAX;
@@ -2673,18 +2683,22 @@
{
struct snd_pcm_runtime *runtime = substream->runtime;
if (atomic_read(&substream->mmap_count))
- return runtime->oss.prev_hw_ptr_interrupt != runtime->hw_ptr_interrupt;
+ return runtime->oss.prev_hw_ptr_period !=
+ get_hw_ptr_period(runtime);
else
- return snd_pcm_playback_avail(runtime) >= runtime->oss.period_frames;
+ return snd_pcm_playback_avail(runtime) >=
+ runtime->oss.period_frames;
}
static int snd_pcm_oss_capture_ready(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
if (atomic_read(&substream->mmap_count))
- return runtime->oss.prev_hw_ptr_interrupt != runtime->hw_ptr_interrupt;
+ return runtime->oss.prev_hw_ptr_period !=
+ get_hw_ptr_period(runtime);
else
- return snd_pcm_capture_avail(runtime) >= runtime->oss.period_frames;
+ return snd_pcm_capture_avail(runtime) >=
+ runtime->oss.period_frames;
}
static unsigned int snd_pcm_oss_poll(struct file *file, poll_table * wait)