From: Clemens Ladisch <[email protected]> ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
commit b1d4f7f4bdcf9915c41ff8cfc4425c84dabb1fde upstream. If a timer interrupt was delayed too much, hrtimer_forward_now() will forward the timer expiry more than once. When this happens, the additional number of elapsed ALSA timer ticks must be passed to snd_timer_interrupt() to prevent the ALSA timer from falling behind. This mostly fixes MIDI slowdown problems on highly-loaded systems with badly behaved interrupt handlers. Signed-off-by: Clemens Ladisch <[email protected]> Reported-and-tested-by: Arthur Marsh <[email protected]> Signed-off-by: Takashi Iwai <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- sound/core/hrtimer.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/sound/core/hrtimer.c b/sound/core/hrtimer.c index 7730575..07efa29 100644 --- a/sound/core/hrtimer.c +++ b/sound/core/hrtimer.c @@ -45,12 +45,13 @@ static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt) { struct snd_hrtimer *stime = container_of(hrt, struct snd_hrtimer, hrt); struct snd_timer *t = stime->timer; + unsigned long oruns; if (!atomic_read(&stime->running)) return HRTIMER_NORESTART; - hrtimer_forward_now(hrt, ns_to_ktime(t->sticks * resolution)); - snd_timer_interrupt(stime->timer, t->sticks); + oruns = hrtimer_forward_now(hrt, ns_to_ktime(t->sticks * resolution)); + snd_timer_interrupt(stime->timer, t->sticks * oruns); if (!atomic_read(&stime->running)) return HRTIMER_NORESTART; -- 1.7.4.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
