在 2023年8月29日星期二 CST 上午1:28:22，Laurent Pinchart 写道：
> Hi Zhang,
>
> Thank you for the patch.
>
> On Tue, Aug 29, 2023 at 12:55:01AM +0800, Zhang Shurong wrote:
> > of_match_device() may fail and returns a NULL pointer.
>
> How can it return a NULL pointer here ?
>
> > Fix this by checking the return value of of_match_device().
> >
> > Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp")
> > Signed-off-by: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
> > ---
> >
> > drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
> > b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c index
> > 7984da9c0a35..d272f35c8eac 100644
> > --- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
> > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
> > @@ -488,6 +488,8 @@ static int imx8qxp_ldb_parse_dt_companion(struct
> > imx8qxp_ldb *imx8qxp_ldb)>
> > * string.
> > */
> >
> > match = of_match_device(dev->driver->of_match_table, dev);
> >
> > + if (!match)
> > + return -ENODEV;
> >
> > if (!of_device_is_compatible(companion, match->compatible)) {
> >
> > DRM_DEV_ERROR(dev, "companion LDB is incompatible\n");
> > ret = -ENXIO;
I think we can make it happen by designing the platform device in a way that
its name aligns with that of the driver. In such a scenario, when the driver
is probed, the of_match_device function will return null. You can verify this
functionality by reviewing the following function:
static int platform_match(struct device *dev, struct device_driver *drv)
