Re: [PATCH 13/14] drm/bridge: synopsys: Add DW HDMI QP TX controller driver

Sam Ravnborg
2024-06-04T20:41:30Z

Hi Cristian.

On Tue, Jun 04, 2024 at 10:32:04PM +0300, Cristian Ciocaltea wrote:
> Hi Sam,
>
> On 6/1/24 5:32 PM, Sam Ravnborg wrote:
> > Hi Cristian,
> >
> > a few drive-by comments below.
> >
> > Sam
> >
> >
> >> +
> >> +static const struct drm_connector_funcs dw_hdmi_qp_connector_funcs = {
> >> + .fill_modes = drm_helper_probe_single_connector_modes,
> >> + .detect = dw_hdmi_connector_detect,
> >> + .destroy = drm_connector_cleanup,
> >> + .force = dw_hdmi_qp_connector_force,
> >> + .reset = drm_atomic_helper_connector_reset,
> >> + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> >> + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> >> +};
> >> +
> >> +static int dw_hdmi_qp_bridge_attach(struct drm_bridge *bridge,
> >> + enum drm_bridge_attach_flags flags)
> >> +{
> >> + struct dw_hdmi *hdmi = bridge->driver_private;
> >> +
> >> + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
> >> + return drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
> >> + bridge, flags);
> >> +
> >> + return dw_hdmi_connector_create(hdmi, &dw_hdmi_qp_connector_funcs);
> >> +}
> >
> > Are there any users left that requires the display driver to create the
> > connector?
> > In other words - could this driver fail if DRM_BRIDGE_ATTACH_NO_CONNECTOR
> > is not passed and drop dw_hdmi_connector_create()?
> >
> > I did not try to verify this - just a naive question.
>
> I've just tested this and it doesn't work - dw_hdmi_connector_create()
> is still needed.

Hmm, seems the display driver or some other bridge driver fails to
support "DRM_BRIDGE_ATTACH_NO_CONNECTOR".
what other drivers are involved?

Note that my comments here should be seen as potential future
improvements, and do not block the patch from being used.

Sam