+ Linux regression. This is a regression on v6.8-rc1. On Mon, Feb 12, 2024 at 12:07:06PM +0100, Roland Hieber wrote: > On Thu, Feb 08, 2024 at 12:58:02PM -0300, Hiago De Franco wrote: > > Hello all, > > > > while doing some tests with kernel v6.8-rc3 and Colibri iMX7D, we > > noticed the following error: > > > > [ 0.432547] mxsfb 30730000.lcdif: error -ENODEV: Cannot connect bridge > > > > This was introduced by commit edbbae7fba495284f72f05768696572691231558 > > ("ARM: dts: imx7: add MIPI-DSI support"). This patch is routing the > > lcdif to the mipi_dsi_in_lcdif endpoint, however we do not have the DSI > > pins available in our edge connector. Instead, we use the parallel RGB > > LCD interface directly with, as example, an external LVDS transmitter: > > > > &lcdif { > > ... > > status = "disabled"; > > > > port { > > lcdif_out: endpoint { > > remote-endpoint = <&lcd_panel_in>; > > }; > > }; > > }; > > > > By applying the following patch, the issue is gone and the LVDS works > > again: > > > > diff --git a/arch/arm/boot/dts/nxp/imx/imx7s.dtsi b/arch/arm/boot/dts/nxp/imx/imx7s.dtsi > > index ebf7befcc11e..9c81c6baa2d3 100644 > > --- a/arch/arm/boot/dts/nxp/imx/imx7s.dtsi > > +++ b/arch/arm/boot/dts/nxp/imx/imx7s.dtsi > > @@ -834,16 +834,6 @@ lcdif: lcdif@30730000 { > > <&clks IMX7D_LCDIF_PIXEL_ROOT_CLK>; > > clock-names = "pix", "axi"; > > status = "disabled"; > > - > > - port { > > - #address-cells = <1>; > > - #size-cells = <0>; > > - > > - lcdif_out_mipi_dsi: endpoint@0 { > > - reg = <0>; > > - remote-endpoint = <&mipi_dsi_in_lcdif>; > > - }; > > - }; > > }; > > > > mipi_csi: mipi-csi@30750000 { > > @@ -895,22 +885,6 @@ mipi_dsi: dsi@30760000 { > > samsung,esc-clock-frequency = <20000000>; > > samsung,pll-clock-frequency = <24000000>; > > status = "disabled"; > > - > > - ports { > > - #address-cells = <1>; > > - #size-cells = <0>; > > - > > - port@0 { > > - reg = <0>; > > - #address-cells = <1>; > > - #size-cells = <0>; > > - > > - mipi_dsi_in_lcdif: endpoint@0 { > > - reg = <0>; > > - remote-endpoint = <&lcdif_out_mipi_dsi>; > > - }; > > - }; > > - }; > > }; > > }; > > > > I would like to know your opinion about this patch before sending it, > > does it makes sense for you? I understand that routing to endpoint > > should be done in the SoM device tree, so we are free to rout other > > endpoint without issues. > > As far as I understood, the LCDIF -> DSI connection is always present in > the SoC. Can you overwrite the routing in your dts like this:? > > &lcdif_out_mipi_dsi { > remote-endpoint = <&lcd_panel_in>; > }; > > I'm not sure what is the best default solution here for imx7s.dtsi. Also > the labels don't work out in that case, this could be improved. For sure for something to be defined a solution it should not introduce regressions :-) This commit makes other boards not work anymore, specifically this reports is about colibri-imx7. With that said, the following patch solves the issue diff --git a/arch/arm/boot/dts/nxp/imx/imx7-colibri.dtsi b/arch/arm/boot/dts/nxp/imx/imx7-colibri.dtsi index 9fe51884af79..966ad13e7c78 100644 --- a/arch/arm/boot/dts/nxp/imx/imx7-colibri.dtsi +++ b/arch/arm/boot/dts/nxp/imx/imx7-colibri.dtsi @@ -536,12 +536,15 @@ &lcdif { status = "disabled"; port { - lcdif_out: endpoint { + lcdif_out: endpoint@0 { + reg = <0>; remote-endpoint = <&lcd_panel_in>; }; }; }; +/delete-node/ &mipi_dsi_in_lcdif; + /* Colibri PWM<A> */ &pwm1 { pinctrl-names = "default"; However, ... I do not really like the delete node, but it's required to prevent this error: arch/arm/boot/dts/nxp/imx/imx7s.dtsi:908.37-911.9: Warning (graph_endpoint): /soc/bus@30400000/dsi@30760000/ports/port@0/endpoint@0: graph connection to node '/soc/bus@30400000/lcdif@30730000/port/endpoint@0' is not bidirectional With that said, unless you have a better solution I would just send a revert for your change. Francesco