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 <perex@perex.cz>
diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 3c00882..838ad86 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -171,6 +171,10 @@
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 @@
.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,