[PATCH v1] drm/bridge: lt8912b: Add hot plug detection

[Adrien Grassein]

Le mar. 29 nov. 2022 à 12:15, Robert Foss <robert.foss at linaro.org> a écrit :
>
> On Mon, 28 Nov 2022 at 12:23, Francesco Dolcini <francesco at dolcini.it> wrote:
> >
> > From: Stefan Eichenberger <stefan.eichenberger at toradex.com>
> >
> > Enable hot plug detection when it is available on the HDMI port.
> > Without this connecting to a different monitor with incompatible timing
> > before the 10 seconds poll period will lead to a broken display output.
> >
> > Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge")
> > Signed-off-by: Stefan Eichenberger <stefan.eichenberger at toradex.com>
> > Signed-off-by: Francesco Dolcini <francesco.dolcini at toradex.com>
> > ---
> >  drivers/gpu/drm/bridge/lontium-lt8912b.c | 21 +++++++++++++++++++--
> >  1 file changed, 19 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c
> > index a98efef0ba0e..5f0c9cd2a970 100644
> > --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c
> > +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c
> > @@ -517,14 +517,27 @@ static int lt8912_attach_dsi(struct lt8912 *lt)
> >         return 0;
> >  }
> >
> > +static void lt8912_bridge_hpd_cb(void *data, enum drm_connector_status status)
> > +{
> > +       struct lt8912 *lt = data;
> > +
> > +       if (lt->bridge.dev)
> > +               drm_helper_hpd_irq_event(lt->bridge.dev);
> > +}
> > +
> >  static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
> >  {
> >         int ret;
> >         struct lt8912 *lt = bridge_to_lt8912(bridge);
> >         struct drm_connector *connector = &lt->connector;
> >
> > -       connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> > -                           DRM_CONNECTOR_POLL_DISCONNECT;
> > +       if (lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD) {
> > +               drm_bridge_hpd_enable(lt->hdmi_port, lt8912_bridge_hpd_cb, lt);
> > +               connector->polled = DRM_CONNECTOR_POLL_HPD;
> > +       } else {
> > +               connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> > +                                   DRM_CONNECTOR_POLL_DISCONNECT;
> > +       }
> >
> >         ret = drm_connector_init(bridge->dev, connector,
> >                                  &lt8912_connector_funcs,
> > @@ -578,6 +591,10 @@ static void lt8912_bridge_detach(struct drm_bridge *bridge)
> >
> >         if (lt->is_attached) {
> >                 lt8912_hard_power_off(lt);
> > +
> > +               if (lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD)
> > +                       drm_bridge_hpd_disable(lt->hdmi_port);
> > +
> >                 drm_connector_unregister(&lt->connector);
> >                 drm_connector_cleanup(&lt->connector);
> >         }
> > --
> > 2.25.1
> >
>
>
> Reviewed-by: Robert Foss <robert.foss at linaro.org>
Reviewed-by: Adrien Grassein <adrien.grassein at gmail.com>
>
> Snoozing this patch, will apply it in a few days if no issues are found.