From 79452f0a28aa5a40522c487b42a5fc423647ad98 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 22 Jul 2009 12:51:51 +0200 Subject: [PATCH] ALSA: pcm - Fix regressions with VMware VMware tends to report PCM positions and period updates at utterly wrong timing. This screws up the recent PCM core code that tries to correct the position based on the irq timing. Now, when a backward irq position is detected, skip the update instead of rebasing. (This is almost the old behavior before 2.6.30.) Signed-off-by: Takashi Iwai --- sound/core/pcm_lib.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 333e4dd2945..3b673e2f991 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -244,18 +244,27 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream) delta = new_hw_ptr - hw_ptr_interrupt; } if (delta < 0) { - delta += runtime->buffer_size; + if (runtime->periods == 1) + delta += runtime->buffer_size; if (delta < 0) { hw_ptr_error(substream, "Unexpected hw_pointer value " "(stream=%i, pos=%ld, intr_ptr=%ld)\n", substream->stream, (long)pos, (long)hw_ptr_interrupt); +#if 1 + /* simply skipping the hwptr update seems more + * robust in some cases, e.g. on VMware with + * inaccurate timer source + */ + return 0; /* skip this update */ +#else /* rebase to interrupt position */ hw_base = new_hw_ptr = hw_ptr_interrupt; /* align hw_base to buffer_size */ hw_base -= hw_base % runtime->buffer_size; delta = 0; +#endif } else { hw_base += runtime->buffer_size; if (hw_base >= runtime->boundary) -- 2.20.1