On 18/09/2019 11:41:14+0200, Gregory CLEMENT wrote: > A potential bug was reported in the email "[BUG] atmel_ssc_dai: a > possible sleep-in-atomic bug in atmel_ssc_shutdown"[1] > > Indeed in the function atmel_ssc_shutdown() free_irq() was called in a > critical section protected by spinlock. > > However this spinlock is only used in atmel_ssc_shutdown() and > atmel_ssc_startup() functions. After further analysis, it occurred that > the call to these function are already protected by mutex used on the > calling functions. > > Then we can remove the spinlock which will fix this bug as a side > effect. Thanks to this patch the following message disappears: > > "BUG: sleeping function called from invalid context at > kernel/locking/mutex.c:909" > > [1]: https://www.spinics.net/lists/alsa-devel/msg71286.html > > Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx> > --- > sound/soc/atmel/atmel_ssc_dai.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c > index 6f89483ac88c..365957e86419 100644 > --- a/sound/soc/atmel/atmel_ssc_dai.c > +++ b/sound/soc/atmel/atmel_ssc_dai.c > @@ -116,19 +116,16 @@ static struct atmel_pcm_dma_params ssc_dma_params[NUM_SSC_DEVICES][2] = { > static struct atmel_ssc_info ssc_info[NUM_SSC_DEVICES] = { > { > .name = "ssc0", > - .lock = __SPIN_LOCK_UNLOCKED(ssc_info[0].lock), This member is now unused and can be removed from the struct. Once fixed, Reviewed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> > .dir_mask = SSC_DIR_MASK_UNUSED, > .initialized = 0, > }, > { > .name = "ssc1", > - .lock = __SPIN_LOCK_UNLOCKED(ssc_info[1].lock), > .dir_mask = SSC_DIR_MASK_UNUSED, > .initialized = 0, > }, > { > .name = "ssc2", > - .lock = __SPIN_LOCK_UNLOCKED(ssc_info[2].lock), > .dir_mask = SSC_DIR_MASK_UNUSED, > .initialized = 0, > }, > @@ -317,13 +314,11 @@ static int atmel_ssc_startup(struct snd_pcm_substream *substream, > > snd_soc_dai_set_dma_data(dai, substream, dma_params); > > - spin_lock_irq(&ssc_p->lock); > if (ssc_p->dir_mask & dir_mask) { > spin_unlock_irq(&ssc_p->lock); > return -EBUSY; > } > ssc_p->dir_mask |= dir_mask; > - spin_unlock_irq(&ssc_p->lock); > > return 0; > } > @@ -355,7 +350,6 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream, > > dir_mask = 1 << dir; > > - spin_lock_irq(&ssc_p->lock); > ssc_p->dir_mask &= ~dir_mask; > if (!ssc_p->dir_mask) { > if (ssc_p->initialized) { > @@ -369,7 +363,6 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream, > ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0; > ssc_p->forced_divider = 0; > } > - spin_unlock_irq(&ssc_p->lock); > > /* Shutdown the SSC clock. */ > pr_debug("atmel_ssc_dai: Stopping clock\n"); > -- > 2.23.0 > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
