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Commit 0db71023 authored by Jaroslav Kysela's avatar Jaroslav Kysela
Browse files

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: default avatarJaroslav Kysela <perex@perex.cz>
parent 838c364f

sound/drivers/aloop.c

+7 −1
Original line number Diff line number Diff line
@@ -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,