lkml.org 
[lkml]   [2019]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] iio: cros_ec_accel_legacy: Always release lock when returning from _read()
Hi Benson,

On Mon, Jul 15, 2019 at 12:55:57PM -0700, Benson Leung wrote:
> Hi Matthias,
>
> On Mon, Jul 15, 2019 at 12:10:17PM -0700, Matthias Kaehlcke wrote:
> > Before doing any actual work cros_ec_accel_legacy_read() acquires
> > a mutex, which is released at the end of the function. However for
> > 'calibbias' channels the function returns directly, without releasing
> > the lock. The next attempt to acquire the lock blocks forever. Instead
> > of an explicit return statement use the common return path, which
> > releases the lock.
> >
> > Fixes: 11b86c7004ef1 ("platform/chrome: Add cros_ec_accel_legacy driver")
> > Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> > ---
> > drivers/iio/accel/cros_ec_accel_legacy.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c
> > index 46bb2e421bb9..27ca4a64dddf 100644
> > --- a/drivers/iio/accel/cros_ec_accel_legacy.c
> > +++ b/drivers/iio/accel/cros_ec_accel_legacy.c
> > @@ -206,7 +206,8 @@ static int cros_ec_accel_legacy_read(struct iio_dev *indio_dev,
> > case IIO_CHAN_INFO_CALIBBIAS:
> > /* Calibration not supported. */
> > *val = 0;
> > - return IIO_VAL_INT;
> > + ret = IIO_VAL_INT;
> > + break;
>
> The value of ret is not used below this. It seems to be only used in
> case IIO_CHAN_INFO_RAW. In fact, with your change,
> there's no return value at all and we just reach the end of
> cros_ec_accel_legacy_read.
>
> > default:
> > return -EINVAL;
> > }
>

I messed up. I was over-confident that a FROMLIST patch in our 4.19
kernel + this patch applying on upstream means that upstream uses the
same code. I should have double-checked that the upstream context is
actually the same.

Sorry for the noise.

\
 
 \ /
  Last update: 2019-07-15 22:08    [W:0.071 / U:0.456 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site