On Thu, 6 Jun 2019 15:13:00 +0200 Pavel Machek <pa...@ucw.cz> wrote: > (stable removed from cc list) > > > Indio->mlock is used for protecting the different iio device modes. > > It is currently not being used in this way. Replace the lock with > > an internal lock specifically used for protecting the SPI transfer > > buffer. > > > > Signed-off-by: Justin Chen <justinpo...@gmail.com> > > Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com> > > Signed-off-by: Sasha Levin <sas...@kernel.org> > > --- > > drivers/iio/adc/ti-ads7950.c | 19 +++++++++++++++---- > > 1 file changed, 15 insertions(+), 4 deletions(-) > > > > > @@ -277,6 +280,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, > > void *p) > > struct ti_ads7950_state *st = iio_priv(indio_dev); > > int ret; > > > > + mutex_lock(&st->slock); > > ret = spi_sync(st->spi, &st->ring_msg); > > if (ret < 0) > > goto out; > > @@ -285,6 +289,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, > > void *p) > > iio_get_time_ns(indio_dev)); > > > > out: > > + mutex_unlock(&st->slock); > > iio_trigger_notify_done(indio_dev->trig); > > > > return IRQ_HANDLED; > > Does trigger_handler run from interrupt context? Prototype suggests > so... If so, it can not really take mutexes...
It's an interrupt thread so taking mutexes should be fine. For this particular case there is no 'top half' provided to the call to iio_triggered_buffer_setup so nothing runs in interrupt context. The spi_sync call can sleep anyway so this code can only run where sleeping is fine. Thanks, Jonathan > > Best regards, > Pavel >
