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authorClemens Ladisch <clemens@ladisch.de>2010-05-21 09:15:59 +0200
committerTakashi Iwai <tiwai@suse.de>2010-05-21 16:33:34 +0200
commitead4046b2fdfd69acc4272e693afd249ad3eb689 (patch)
tree9dbc91adb9f4c654f6b9eaa245422162f12e8e47 /sound/core/pcm_lib.c
parent7f06a8b26aba1dc03b42272dc0089a800372c575 (diff)
ALSA: pcm: fix the fix of the runtime->boundary calculation
Commit 7910b4a1db63fefc3d291853d33c34c5b6352e8e in 2.6.34 changed the runtime->boundary calculation to make this value a multiple of both the buffer_size and the period_size, because the latter is assumed by the runtime->hw_ptr_interrupt calculation. However, due to the lack of a ioctl that could read the software parameters before they are set, the kernel requires that alsa-lib calculates the boundary value, too. The changed algorithm leads to a different boundary value used by alsa-lib, which makes, e.g., mplayer fail to play a 44.1 kHz file because the silence_size parameter is now invalid; bug report: <https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5015>. This patch reverts the change to the boundary calculation, and instead fixes the hw_ptr_interrupt calculation to be period-aligned regardless of the boundary value. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/pcm_lib.c')
-rw-r--r--sound/core/pcm_lib.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index a2ff86189d2a..22aff180dd1f 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -439,8 +439,13 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
snd_pcm_playback_silence(substream, new_hw_ptr);
if (in_interrupt) {
- runtime->hw_ptr_interrupt = new_hw_ptr -
- (new_hw_ptr % runtime->period_size);
+ delta = new_hw_ptr - runtime->hw_ptr_interrupt;
+ if (delta < 0)
+ delta += runtime->boundary;
+ delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
+ runtime->hw_ptr_interrupt += delta;
+ if (runtime->hw_ptr_interrupt >= runtime->boundary)
+ runtime->hw_ptr_interrupt -= runtime->boundary;
}
runtime->hw_ptr_base = hw_base;
runtime->status->hw_ptr = new_hw_ptr;