On Fri, Mar 17, 2017 at 08:41:11PM +0530, sayli karnik wrote:
> iio_dev->mlock should be used by the IIO core only for protecting
> device operating mode changes. ie. Changes between INDIO_DIRECT_MODE,
> INDIO_BUFFER_* modes.
> Replace mlock with a lock in the device's global data to protect
> hardware state changes.
Hi Sayli,
There are nested locks here, hence deadlock. I'm wondering if we can grab
the lock once at the top layers (read/write_raw functions) and hold it.
Seems like that's a pattern in IIO drivers. Let's see what the reviewers
suggest on this one.
alisons
>
> Signed-off-by: sayli karnik <karniksayli1995@xxxxxxxxx>
> ---
> drivers/staging/iio/meter/ade7758_core.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/iio/meter/ade7758_core.c b/drivers/staging/iio/meter/ade7758_core.c
> index 99c89e6..1723eb8 100644
> --- a/drivers/staging/iio/meter/ade7758_core.c
> +++ b/drivers/staging/iio/meter/ade7758_core.c
> @@ -522,13 +522,14 @@ static int ade7758_read_raw(struct iio_dev *indio_dev,
> int *val2,
> long mask)
> {
> + struct ade7758_state *st = iio_priv(indio_dev);
> int ret;
>
> switch (mask) {
> case IIO_CHAN_INFO_SAMP_FREQ:
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->buf_lock);
> ret = ade7758_read_samp_freq(&indio_dev->dev, val);
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->buf_lock);
> return ret;
> default:
> return -EINVAL;
> @@ -541,15 +542,16 @@ static int ade7758_write_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int val, int val2, long mask)
> {
> + struct ade7758_state *st = iio_priv(indio_dev);
> int ret;
>
> switch (mask) {
> case IIO_CHAN_INFO_SAMP_FREQ:
> if (val2)
> return -EINVAL;
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->buf_lock);
> ret = ade7758_write_samp_freq(&indio_dev->dev, val);
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->buf_lock);
> return ret;
> default:
> return -EINVAL;
> --
> 2.7.4
>
> --
> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@xxxxxxxxxxxxxxxx.
> To post to this group, send email to outreachy-kernel@xxxxxxxxxxxxxxxx.
> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170317151110.GA26848%40sayli-HP-15-Notebook-PC.
> For more options, visit https://groups.google.com/d/optout.
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
