commit
d4f1e48bd11e3df6a26811f7a1f06c4225d92f7d upstream.
When the loopback timer handler is running, calling del_timer() (for STOP
trigger) will not wait for the handler to complete before deactivating the
timer. The timer gets rescheduled in the handler as usual. Then a subsequent
START trigger will try to start the timer using add_timer() with a timer pending
leading to a kernel panic.
Serialize the calls to add_timer() and del_timer() using a spin lock to avoid
this.
Signed-off-by: Omair Mohammed Abdullah <omair.m.abdullah@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
unsigned int period_size_frac;
unsigned long last_jiffies;
struct timer_list timer;
unsigned int period_size_frac;
unsigned long last_jiffies;
struct timer_list timer;
};
static struct platform_device *devices[SNDRV_CARDS];
};
static struct platform_device *devices[SNDRV_CARDS];
unsigned long tick;
unsigned int rate_shift = get_rate_shift(dpcm);
unsigned long tick;
unsigned int rate_shift = get_rate_shift(dpcm);
+ spin_lock(&dpcm->timer_lock);
if (rate_shift != dpcm->pcm_rate_shift) {
dpcm->pcm_rate_shift = rate_shift;
dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
if (rate_shift != dpcm->pcm_rate_shift) {
dpcm->pcm_rate_shift = rate_shift;
dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
dpcm->timer.expires = jiffies + tick;
add_timer(&dpcm->timer);
tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
dpcm->timer.expires = jiffies + tick;
add_timer(&dpcm->timer);
+ spin_unlock(&dpcm->timer_lock);
}
static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
{
}
static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
{
+ spin_lock(&dpcm->timer_lock);
del_timer(&dpcm->timer);
dpcm->timer.expires = 0;
del_timer(&dpcm->timer);
dpcm->timer.expires = 0;
+ spin_unlock(&dpcm->timer_lock);
}
#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
}
#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
dpcm->substream = substream;
setup_timer(&dpcm->timer, loopback_timer_function,
(unsigned long)dpcm);
dpcm->substream = substream;
setup_timer(&dpcm->timer, loopback_timer_function,
(unsigned long)dpcm);
+ spin_lock_init(&dpcm->timer_lock);
cable = loopback->cables[substream->number][dev];
if (!cable) {
cable = loopback->cables[substream->number][dev];
if (!cable) {