From 0db710230589b5571c23f59250eabc9504b17c98 Mon Sep 17 00:00:00 2001 From: Jaroslav Kysela Date: Thu, 14 Oct 2010 21:46:12 +0200 Subject: [PATCH] ALSA: snd-aloop - fix issue in the timer start function In some circumstances (the rate shift value was changed), the irq_pos value may be higher than the fraction value in the timer start function. Check for it. Also, to avoid value overflow, decrease maximum period size. Signed-off-by: Jaroslav Kysela --- sound/drivers/aloop.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index 3c00882..838ad863 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -171,6 +171,10 @@ static void loopback_timer_start(struct loopback_pcm *dpcm) dpcm->pcm_rate_shift = rate_shift; dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size); } + if (dpcm->period_size_frac <= dpcm->irq_pos) { + dpcm->irq_pos %= dpcm->period_size_frac; + dpcm->period_update_pending = 1; + } tick = dpcm->period_size_frac - dpcm->irq_pos; tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps; dpcm->timer.expires = jiffies + tick; @@ -531,7 +535,9 @@ static struct snd_pcm_hardware loopback_pcm_hardware = .channels_max = 32, .buffer_bytes_max = 2 * 1024 * 1024, .period_bytes_min = 64, - .period_bytes_max = 2 * 1024 * 1024, + /* note check overflow in frac_pos() using pcm_rate_shift before + changing period_bytes_max value */ + .period_bytes_max = 1024 * 1024, .periods_min = 1, .periods_max = 1024, .fifo_size = 0, -- 2.7.4