[PATCH] drm:bridge:analogix: Fix refcount bugs in anx7625_parse_dt()

[Robert Foss]

On Mon, 18 Jul 2022 at 13:54, Robert Foss <robert.foss at linaro.org> wrote:
>
> Hey Liang,
>
>
> On Thu, 7 Jul 2022 at 03:25, Liang He <windhl at 126.com> wrote:
> >
> > There are two refcount bugs in this funcion:
> >
> > BUG-1: 'pdata->mipi_host_node' will be assigned a new reference with
> > of_graph_get_remote_node() which will increase the refcount of the
> > object, correspondingly, we should call of_node_put() for the old
> > reference stored in the 'pdata->mipi_host_node'.
> >
> > BUG-2: of_graph_get_endpoint_by_regs() will also increase the refcount
> > of the object and its new reference will be assigned to local 'ep0', so
> > there should be a of_node_put() when 'ep0' is not used anymore.
> >
> > Fixes: 8bdfc5dae4e3 ("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")
> > Fixes: fd0310b6fe7d ("drm/bridge: anx7625: add MIPI DPI input feature")
> > Signed-off-by: Liang He <windhl at 126.com>
> > ---
> >  drivers/gpu/drm/bridge/analogix/anx7625.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > index 53a5da6c49dd..f39b9be19eaf 100644
> > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > @@ -1624,6 +1624,7 @@ static int anx7625_parse_dt(struct device *dev,
> >         anx7625_get_swing_setting(dev, pdata);
> >
> >         pdata->is_dpi = 1; /* default dpi mode */
> > +       of_node_put(pdata->mipi_host_node);
> >         pdata->mipi_host_node = of_graph_get_remote_node(np, 0, 0);
> >         if (!pdata->mipi_host_node) {
> >                 DRM_DEV_ERROR(dev, "fail to get internal panel.\n");
> > @@ -1638,6 +1639,7 @@ static int anx7625_parse_dt(struct device *dev,
> >                         bus_type = 0;
> >
> >                 mipi_lanes = of_property_count_u32_elems(ep0, "data-lanes");
> > +               of_node_put(ep0);
> >         }
> >
> >         if (bus_type == V4L2_FWNODE_BUS_TYPE_PARALLEL) /* bus type is Parallel(DSI) */
> > --
> > 2.25.1
> >
>
> This patch does not apply on drm-misc-next, could you please rebase it
> and send a v2?

Can you also fix the title, it should start with "drm/bridge: anx7625:"