[ALSA] pcm core: fix silence_start calculations

The case where silence_size < boundary was broken because different
parts of the snd_pcm_playback_silence() function disagreed about whether
silence_start should point to the start or to the end of the buffer part
to be silenced.
This patch changes the code to always use to the start, which also
simplifies several calculations.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 0bb142a28539fe93c6be231b715b076821a33b3f..b336797be4fc877f4cd2ff0e8fa1e9e184ff2774 100644 (file)
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -79,19 +79,17 @@ 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 = (ofs + frames) - runtime->buffer_size;
+                               runtime->silence_start = new_hw_ptr;
                        } else {
-                               runtime->silence_start = ofs - runtime->silence_filled;
+                               runtime->silence_start = ofs;
                        }
-                       if ((snd_pcm_sframes_t)runtime->silence_start < 0)
-                               runtime->silence_start += runtime->boundary;
                }
                frames = runtime->buffer_size - runtime->silence_filled;
        }
        snd_assert(frames <= runtime->buffer_size, return);
        if (frames == 0)
                return;
-       ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size;
+       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 ||