Commit 781b4da6 authored by Jaroslav Kysela's avatar Jaroslav Kysela Committed by Takashi Iwai
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ALSA: pcm: fix playback silence - correct incremental silencing 



Commit 9a826ddb ("[ALSA] pcm core: fix silence_start calculations")
came with exactly the right commit message, but the patch just made
things broken in a different way: We'd fill at a too low address if the
area was already partially zeroed, so we'd under-fill. This affected
both thresholded mode (where it was somewhat less likely) and top-up
mode (where it would be the case consistently).

Co-developed-by: default avatarOswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: default avatarOswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: default avatarJaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230505155244.2312199-3-oswald.buddenhagen@gmx.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 2fbaa44a

sound/core/pcm_lib.c

+3 −7
Original line number Diff line number Diff line
@@ -87,9 +87,7 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram 
			if (avail > runtime->buffer_size)

				avail = runtime->buffer_size;

			runtime->silence_filled = avail > 0 ? avail : 0;

			runtime->silence_start = (runtime->status->hw_ptr +

						  runtime->silence_filled) %

						 runtime->boundary;

			runtime->silence_start = runtime->status->hw_ptr;

		} else {

			ofs = runtime->status->hw_ptr;

			frames = new_hw_ptr - ofs;
@@ -98,10 +96,8 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram 
			runtime->silence_filled -= frames;

			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {

				runtime->silence_filled = 0;

				runtime->silence_start = new_hw_ptr;

			} else {

				runtime->silence_start = ofs;

			}

			runtime->silence_start = new_hw_ptr;

		}

		frames = runtime->buffer_size - runtime->silence_filled;

	}
@@ -109,7 +105,7 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram 
		return;

	if (frames == 0)

		return;

	ofs = runtime->silence_start % runtime->buffer_size;

	ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size;

	while (frames > 0) {

		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;

		err = fill_silence_frames(substream, ofs, transfer);