Re: [PATCH] drm/lcdif: switch to DRM_BRIDGE_ATTACH_NO_CONNECTOR

[Alexander Stein <alexander.stein@ew.tq-group.com>]

Hi Dmitry,

Am Montag, 24. Juni 2024, 13:49:03 CEST schrieb Dmitry Baryshkov:
> On Mon, 24 Jun 2024 at 14:32, Alexander Stein
> <alexander.stein@ew.tq-group.com> wrote:
> >
> > Hi,
> >
> > Am Montag, 24. Juni 2024, 12:31:46 CEST schrieb Dmitry Baryshkov:
> > > Existing in-kernel device trees use LCDIF with the dsim + adv7533, dsim
> > > + tc358762 or with ldb + panel_bridge. All these combinations support
> > > using DRM_BRIDGE_ATTACH_NO_CONNECTOR for bridge attachment.
> > >
> > > Change lcdif driver to use this flag when attaching the bridge and
> > > create drm_bridge_connector afterwards.
> > >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > > ---
> > > Note: compile-tested only.
> >
> > I gave it a try, but it doesn't work. Despite DSI output it also breaks
> > HDMI output, where I at least some error messages:
> > [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@32c00000/hdmi@32fd8000 to encoder None-37: -22
> > [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@32c00000/display-bridge@32fc4000 to encoder None-37: -22
> > imx-lcdif 32fc6000.display-controller: error -EINVAL: Failed to attach bridge for endpoint0
> > imx-lcdif 32fc6000.display-controller: error -EINVAL: Cannot connect bridge
> > imx-lcdif 32fc6000.display-controller: probe with driver imx-lcdif failed with error -22
> 
> Could you please try it with the following change:
> 
> diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> index 13bc570c5473..c87d3e55c00d 100644
> --- a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> +++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> @@ -94,6 +94,7 @@ static int imx8mp_dw_hdmi_probe(struct platform_device *pdev)
>         plat_data->phy_name = "SAMSUNG HDMI TX PHY";
>         plat_data->priv_data = hdmi;
>         plat_data->phy_force_vendor = true;
> +       plat_data->output_port = 1;
> 
>         hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
>         if (IS_ERR(hdmi->dw_hdmi))

Okay, this does fix the HDMI probe errors. Nevertheless I get the errors:
[   13.429313] [drm] Initialized imx-lcdif 1.0.0 for 32e80000.display-controller on minor 1
[   13.439116] imx-lcdif 32e80000.display-controller: [drm] Cannot find any crtc or sizes
[   13.448168] imx-lcdif 32e80000.display-controller: [drm] Cannot find any crtc or sizes
[   15.519737] [drm] Initialized imx-lcdif 1.0.0 for 32fc6000.display-controller on minor 2
[   15.675672] imx-lcdif 32fc6000.display-controller: [drm] Cannot find any crtc or sizes

just from the lcdif patch for both HDMI and DP.

Best regards,
Alexander

> 
> >
> > Best regards,
> > Alexander
> >
> > > ---
> > >  drivers/gpu/drm/mxsfb/lcdif_drv.c | 14 +++++++++++++-
> > >  1 file changed, 13 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/mxsfb/lcdif_drv.c b/drivers/gpu/drm/mxsfb/lcdif_drv.c
> > > index 0f895b8a99d6..1d5508449995 100644
> > > --- a/drivers/gpu/drm/mxsfb/lcdif_drv.c
> > > +++ b/drivers/gpu/drm/mxsfb/lcdif_drv.c
> > > @@ -16,6 +16,7 @@
> > >
> > >  #include <drm/drm_atomic_helper.h>
> > >  #include <drm/drm_bridge.h>
> > > +#include <drm/drm_bridge_connector.h>
> > >  #include <drm/drm_drv.h>
> > >  #include <drm/drm_encoder.h>
> > >  #include <drm/drm_fbdev_dma.h>
> > > @@ -48,6 +49,7 @@ static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
> > >  {
> > >       struct device *dev = lcdif->drm->dev;
> > >       struct device_node *ep;
> > > +     struct drm_connector *connector;
> > >       struct drm_bridge *bridge;
> > >       int ret;
> > >
> > > @@ -96,13 +98,23 @@ static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
> > >                       return ret;
> > >               }
> > >
> > > -             ret = drm_bridge_attach(encoder, bridge, NULL, 0);
> > > +             ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > >               if (ret) {
> > >                       of_node_put(ep);
> > >                       return dev_err_probe(dev, ret,
> > >                                            "Failed to attach bridge for endpoint%u\n",
> > >                                            of_ep.id);
> > >               }
> > > +
> > > +             connector = drm_bridge_connector_init(lcdif->drm, encoder);
> > > +             if (IS_ERR(connector)) {
> > > +                     ret = PTR_ERR(connector);
> > > +                     of_node_put(ep);
> > > +
> > > +                     return dev_err_probe(dev, ret,
> > > +                                          "Failed to create bridge connector for endpoint%u\n",
> > > +                                          of_ep.id);
> > > +             }
> > >       }
> > >
> > >       return 0;
> > >
> > > ---
> > > base-commit: f76698bd9a8ca01d3581236082d786e9a6b72bb7
> > > change-id: 20240624-mxc-lcdif-bridge-attach-60368807b2f9
> > >
> > > Best regards,
> > >
> >
> >
> > --
> > TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
> > Amtsgericht München, HRB 105018
> > Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
> > http://www.tq-group.com/
> >
> >
> 
> 
> 


-- 
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/