From ead4046b2fdfd69acc4272e693afd249ad3eb689 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Fri, 21 May 2010 09:15:59 +0200 Subject: [PATCH] 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: . 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 Cc: Signed-off-by: Takashi Iwai --- sound/core/pcm_lib.c | 9 +++++++-- sound/core/pcm_native.c | 39 +++------------------------------------ 2 files changed, 10 insertions(+), 38 deletions(-) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index a2ff86189d2..22aff180dd1 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; diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 644c2bb17b8..303ac04ff6e 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -27,7 +27,6 @@ #include #include #include -#include #include #include #include @@ -370,38 +369,6 @@ static int period_to_usecs(struct snd_pcm_runtime *runtime) return usecs; } -static int calc_boundary(struct snd_pcm_runtime *runtime) -{ - u_int64_t boundary; - - boundary = (u_int64_t)runtime->buffer_size * - (u_int64_t)runtime->period_size; -#if BITS_PER_LONG < 64 - /* try to find lowest common multiple for buffer and period */ - if (boundary > LONG_MAX - runtime->buffer_size) { - u_int32_t remainder = -1; - u_int32_t divident = runtime->buffer_size; - u_int32_t divisor = runtime->period_size; - while (remainder) { - remainder = divident % divisor; - if (remainder) { - divident = divisor; - divisor = remainder; - } - } - boundary = div_u64(boundary, divisor); - if (boundary > LONG_MAX - runtime->buffer_size) - return -ERANGE; - } -#endif - if (boundary == 0) - return -ERANGE; - runtime->boundary = boundary; - while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size) - runtime->boundary *= 2; - return 0; -} - static int snd_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { @@ -477,9 +444,9 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, runtime->stop_threshold = runtime->buffer_size; runtime->silence_threshold = 0; runtime->silence_size = 0; - err = calc_boundary(runtime); - if (err < 0) - goto _error; + runtime->boundary = runtime->buffer_size; + while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size) + runtime->boundary *= 2; snd_pcm_timer_resolution_change(substream); runtime->status->state = SNDRV_PCM_STATE_SETUP;