lkml.org 
[lkml]   [2011]   [Feb]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[patch 084/176] ALSA: hrtimer: handle delayed timer interrupts
    2.6.36-stable review patch.  If anyone has any objections, please let us know.

    ------------------

    From: Clemens Ladisch <clemens@ladisch.de>

    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 <clemens@ladisch.de>
    Reported-and-tested-by: Arthur Marsh <arthur.marsh@internode.on.net>
    Signed-off-by: Takashi Iwai <tiwai@suse.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    sound/core/hrtimer.c | 5 +++--
    1 file changed, 3 insertions(+), 2 deletions(-)

    --- a/sound/core/hrtimer.c
    +++ b/sound/core/hrtimer.c
    @@ -45,12 +45,13 @@ static enum hrtimer_restart snd_hrtimer_
    {
    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;



    \
     
     \ /
      Last update: 2011-02-16 01:55    [W:6.295 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site