On Wed, 12 Jan 2022 at 20:41, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
>
>
> On 1/6/2022 6:01 PM, Dmitry Baryshkov wrote:
> > In commit 8a3b4c17f863 ("drm/msm/dp: employ bridge mechanism for display
> > enable and disable") the DP driver received a drm_bridge instance, which
> > is always attached to the encoder as a root bridge. However it conflicts
> > with the panel_bridge support for eDP panels. Change panel_bridge
> > attachment to come after dp_bridge attachment.
> >
> > Fixes: 8a3b4c17f863 ("drm/msm/dp: employ bridge mechanism for display enable and disable")
> > Cc: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > ---
> > drivers/gpu/drm/msm/dp/dp_drm.c | 21 +++++++++++----------
> > 1 file changed, 11 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
> > index d4d360d19eba..26ef41a4c1b6 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> > @@ -169,16 +169,6 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
> >
> > drm_connector_attach_encoder(connector, dp_display->encoder);
> >
> > - if (dp_display->panel_bridge) {
> > - ret = drm_bridge_attach(dp_display->encoder,
> > - dp_display->panel_bridge, NULL,
> > - DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > - if (ret < 0) {
> > - DRM_ERROR("failed to attach panel bridge: %d\n", ret);
> > - return ERR_PTR(ret);
> > - }
> > - }
> > -
> > return connector;
> > }
> >
> > @@ -246,5 +236,16 @@ struct drm_bridge *msm_dp_bridge_init(struct msm_dp *dp_display, struct drm_devi
> > return ERR_PTR(rc);
> > }
> >
>
> can check connector_type here and if connector_type ==
> DRM_MODE_CONNECTOR_eDP then no drm_bridge add to eDP? So that eDP only
> has panel_bridge and DP only has drm_bridge?
No, we still need the DP bridge for the eDP. It handles modesetting,
enabling and disabling of the DP controller, etc.
>
> is this fix all your concerns?
>
>
> > + if (dp_display->panel_bridge) {
> > + rc = drm_bridge_attach(dp_display->encoder,
> > + dp_display->panel_bridge, bridge,
> > + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > + if (rc < 0) {
> > + DRM_ERROR("failed to attach panel bridge: %d\n", rc);
> > + drm_bridge_remove(bridge);
> > + return ERR_PTR(rc);
> > + }
> > + }
> > +
> > return bridge;
> > }
--
With best wishes
Dmitry
