[alsa-devel] [PATCH 10/14] ALSA: pcm: Simplify snd_pcm_playback_silence()
Takashi Iwai
tiwai at suse.de
Fri May 26 17:46:59 CEST 2017
On Fri, 26 May 2017 15:21:54 +0200,
Takashi Sakamoto wrote:
>
> On May 26 2017 04:17, Takashi Iwai wrote:
> > Use the existing silence helper codes for simplification.
> >
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> > sound/core/pcm_lib.c | 40 +++++++++++++---------------------------
> > 1 file changed, 13 insertions(+), 27 deletions(-)
> >
> > diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
> > index c24a78e39b88..094447ae8486 100644
> > --- a/sound/core/pcm_lib.c
> > +++ b/sound/core/pcm_lib.c
> > @@ -42,6 +42,9 @@
> > #define trace_hw_ptr_error(substream, reason)
> > #endif
> > +static int fill_silence(struct snd_pcm_substream *substream, int
> > channel,
> > + unsigned long hwoff, void *buf, unsigned long bytes);
> > +
> > /*
> > * fill ring buffer with silence
> > * runtime->silence_start: starting pointer to silence area
> > @@ -55,8 +58,7 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
> > {
> > struct snd_pcm_runtime *runtime = substream->runtime;
> > snd_pcm_uframes_t frames, ofs, transfer;
> > - char *hwbuf;
> > - int err;
> > + int c;
> > if (runtime->silence_size < runtime->boundary) {
> > snd_pcm_sframes_t noise_dist, n;
> > @@ -111,33 +113,17 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
> > transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
> > if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
> > runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
> > - if (substream->ops->fill_silence) {
> > - err = substream->ops->fill_silence(substream, 0,
> > - frames_to_bytes(runtime, ofs),
> > - frames_to_bytes(runtime, transfer));
> > - snd_BUG_ON(err < 0);
> > - } else {
> > - hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
> > - snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
> > - }
> > + fill_silence(substream, 0,
> > + frames_to_bytes(runtime, ofs), NULL,
> > + frames_to_bytes(runtime, transfer));
> > } else {
> > - unsigned int c;
> > - unsigned int channels = runtime->channels;
> > - if (substream->ops->fill_silence) {
> > - for (c = 0; c < channels; ++c) {
> > - err = substream->ops->fill_silence(substream, c,
> > - samples_to_bytes(runtime, ofs),
> > - samples_to_bytes(runtime, transfer));
> > - snd_BUG_ON(err < 0);
> > - }
> > - } else {
> > - size_t dma_csize = runtime->dma_bytes / channels;
> > - for (c = 0; c < channels; ++c) {
> > - hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
> > - snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
> > - }
> > - }
> > + int byte_ofs = samples_to_bytes(runtime, ofs);
> > + int byte_xfer = samples_to_bytes(runtime, transfer);
> > + for (c = 0; c < runtime->channels; ++c)
> > + fill_silence(substream, c, byte_ofs, NULL,
> > + byte_xfer);
> > }
> > +
> > runtime->silence_filled += transfer;
> > frames -= transfer;
> > ofs = 0;
>
> A part of the content inner the while loop can be replaced with added
> 'writer' functions.
Right, we can reuse that.
> And the purpose of this patchset is a kind of
> refactoring, however this drops snd_BUG_ON(). It should be
> remained. Below patch can be squashed to your patch for the points.
Thanks. I prefer just creating a new function instead of calling the
function pointer there. Basically it's easier to read/understand.
The revised patch is below.
Takashi
-- 8< --
From: Takashi Iwai <tiwai at suse.de>
Subject: [PATCH v2] ALSA: pcm: Simplify snd_pcm_playback_silence()
Use the existing silence helper codes for simplification.
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
sound/core/pcm_lib.c | 50 ++++++++++++++++++++------------------------------
1 file changed, 20 insertions(+), 30 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index f15460eaf8b5..a592d3308474 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -42,6 +42,9 @@
#define trace_hw_ptr_error(substream, reason)
#endif
+static int fill_silence_frames(struct snd_pcm_substream *substream,
+ snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
+
/*
* fill ring buffer with silence
* runtime->silence_start: starting pointer to silence area
@@ -55,7 +58,6 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t frames, ofs, transfer;
- char *hwbuf;
int err;
if (runtime->silence_size < runtime->boundary) {
@@ -109,35 +111,8 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
ofs = runtime->silence_start % runtime->buffer_size;
while (frames > 0) {
transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
- if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
- runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
- if (substream->ops->fill_silence) {
- err = substream->ops->fill_silence(substream, 0,
- frames_to_bytes(runtime, ofs),
- frames_to_bytes(runtime, transfer));
- snd_BUG_ON(err < 0);
- } else {
- hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
- snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
- }
- } else {
- unsigned int c;
- unsigned int channels = runtime->channels;
- if (substream->ops->fill_silence) {
- for (c = 0; c < channels; ++c) {
- err = substream->ops->fill_silence(substream, c,
- samples_to_bytes(runtime, ofs),
- samples_to_bytes(runtime, transfer));
- snd_BUG_ON(err < 0);
- }
- } else {
- size_t dma_csize = runtime->dma_bytes / channels;
- for (c = 0; c < channels; ++c) {
- hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
- snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
- }
- }
- }
+ err = fill_silence_frames(substream, ofs, transfer);
+ snd_BUG_ON(err < 0);
runtime->silence_filled += transfer;
frames -= transfer;
ofs = 0;
@@ -2101,6 +2076,21 @@ static int noninterleaved_copy(struct snd_pcm_substream *substream,
return 0;
}
+/* fill silence on the given buffer position;
+ * called from snd_pcm_playback_silence()
+ */
+static int fill_silence_frames(struct snd_pcm_substream *substream,
+ snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
+{
+ if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
+ substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
+ return interleaved_copy(substream, off, NULL, 0, frames,
+ fill_silence);
+ else
+ return noninterleaved_copy(substream, off, NULL, 0, frames,
+ fill_silence);
+}
+
/* sanity-check for read/write methods */
static int pcm_sanity_check(struct snd_pcm_substream *substream)
{
--
2.13.0
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