[PATCH] drm/lcdif: switch to DRM_BRIDGE_ATTACH_NO_CONNECTOR
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Mon Jun 24 05:12:45 PDT 2024
On Mon, 24 Jun 2024 at 15:03, Alexander Stein
<alexander.stein at ew.tq-group.com> wrote:
>
> 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 at 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 at 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 at 0/bus at 32c00000/hdmi at 32fd8000 to encoder None-37: -22
> > > [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc at 0/bus at 32c00000/display-bridge at 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.
It seems, because I'm stupid and I missed drm_connector_attach_encoder().
Anyway, it looks like even if that fixes the issue, dw-hdmi needs more
work to work with drm_bridge_connector without losing access to such
features like YCbCr 420 and CEC. So thank you for the tests, but let's
probably drop the patch / idea for now.
>
> 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/
>
>
--
With best wishes
Dmitry
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