From: Jaroslav Kysela perex@perex.cz
Commit 9a826ddba6e ("[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: Oswald Buddenhagen oswald.buddenhagen@gmx.de Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de Signed-off-by: Jaroslav Kysela perex@perex.cz --- v2: - rewrote commit message - postponed the addition of comments to a subsequent patch where it makes more sense - dropped the part which the subsequent refactoring obsoletes. this reduces the patch to its essentials, making it easier to understand, and reducing churn. --- sound/core/pcm_lib.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 6ad67e7e740c..5ddb74a12030 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -87,29 +87,25 @@ 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; if ((snd_pcm_sframes_t)frames < 0) frames += runtime->boundary; 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; } if (snd_BUG_ON(frames > runtime->buffer_size)) 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);