Quoting Kieran Bingham (2022-11-03 17:27:56)
> Hi Lee,
>
> Quoting lee (2022-11-03 03:14:27)
> > Adds a driver for the 16MPix IMX519 CSI2 sensor.
> > Whilst the sensor supports 2 or 4 CSI2 data lanes, this driver
> > currently only supports 2 lanes.
> >
> > The following Bayer modes are currently available:
> >
> > 4656x3496 10-bit @ 10fps
> > 3840x2160 10-bit (cropped) @ 21fps
> > 2328x1748 10-bit (binned) @ 30fps
> > 1920x1080 10-bit (cropped/binned) @ 60fps
> > 1280x720 10-bit (cropped/binned) @ 120fps
> >
> > Signed-off-by: Lee Jackson <lee@xxxxxxxxxxx>
<snip>
> > +static const struct v4l2_ctrl_ops imx519_ctrl_ops = {
> > + .s_ctrl = imx519_set_ctrl,
> > +};
> > +
> > +static int imx519_enum_mbus_code(struct v4l2_subdev *sd,
> > + struct v4l2_subdev_state *sd_state,
> > + struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > + struct imx519 *imx519 = to_imx519(sd);
> > +
> > + mutex_lock(&imx519->mutex);
> > +
> > + if (code->index > 0)
> > + return -EINVAL;
In fact, this code path returns keeping the lock held ...
I suspect this is the cause of the deadlocks I've seen...
> > +
> > + code->code = imx519_get_format_code(imx519);
> > +
> > + mutex_unlock(&imx519->mutex);
> > +
> > + return 0;
> > +}
> > +
> > +static int imx519_enum_frame_size(struct v4l2_subdev *sd,
> > + struct v4l2_subdev_state *sd_state,
> > + struct v4l2_subdev_frame_size_enum *fse)
> > +{
> > + struct imx519 *imx519 = to_imx519(sd);
> > +
> > + mutex_lock(&imx519->mutex);
>
> I've hit a deadlock here.
>
> [ 139.389907] other info that might help us debug this:
> [ 139.396435] Possible unsafe locking scenario:
> [ 139.396435]
> [ 139.402353] CPU0
> [ 139.404797] ----
> [ 139.407243] lock(&imx519->mutex);
> [ 139.410737] lock(&imx519->mutex);
> [ 139.414230]
> [ 139.414230] *** DEADLOCK ***
> [ 139.414230]
> [ 139.420148] May be due to missing lock nesting notation
> [ 139.420148]
> [ 139.426936] 1 lock held by cam/924:
> [ 139.430425] #0: ffff000003feb460 (&imx519->mutex){+.+.}-{3:3}, at: imx519_enum_mbus_code+0x3
Which should have been obvious if I just read ^^^ that line ;-)
--
Kieran
