Hi Dmitry, On 07/27/2024, Dmitry Baryshkov wrote: > On Fri, Jul 26, 2024 at 02:50:12PM GMT, Liu Ying wrote: >> MCIMX-LVDS1[1] display module integrates a HannStar HSD100PXN1 LVDS >> display panel and a touch IC. Add an overlay to support the LVDS >> panel on i.MX53 QSB / QSRB platforms. >> >> [1] https://www.nxp.com/part/MCIMX-LVDS1 >> >> Signed-off-by: Liu Ying <victor.liu@xxxxxxx> >> --- >> I mark RFC in patch subject prefix because if the DT overlay is used, both ldb >> and panel devices end up as devices deferred. However, if the DT overlay is >> not used and the devices are defined in imx53-qsb-common.dtsi, then they can be >> probed ok. >> >> With a dev_err_probe() added to imx_ldb_probe() in imx-ldb.c, devices_deferred >> indicates 53fa8008.ldb and panel-lvds kind of depend on each other. >> >> root@imx53qsb:~# cat /sys/kernel/debug/devices_deferred >> 53fa8008.ldb imx-ldb: failed to find panel or bridge for channel0 >> panel-lvds platform: wait for supplier /soc/bus@50000000/ldb@53fa8008/lvds-channel@0 >> >> It looks like the issue is related to fw_devlink, because if "fw_devlink=off" >> is added to kernel bootup command line, then the issue doesn't happen. > > Could you please fdtdump /sys/firmware/fdt (or just generated DTB files) > in both cases and compare the dumps for sensible differences? I fdtdump imx53-qsrb-mcimx-lvds1.dtb and imx53-qsrb.dtb. I see three sensible differences. 1) panel-lvds node position. For imx53-qsrb-mcimx-lvds1.dtb, it comes very early and is next to 'compatible = "fsl,imx53-qsrb", "fsl,imx53";'. For imx53-qsrb.dtb, it comes later and is next to panel node in '/' node. 2) properties order in panel-lvds node. For imx53-qsrb-mcimx-lvds1.dtb, it shows panel-lvds { power-supply = <0x0000001c>; backlight = <0x00000030>; compatible = "hannstar,hsd100pxn1"; port { endpoint { phandle = <0x0000007d>; remote-endpoint = <0x0000007c>; }; }; }; For imx53-qsrb.dtb, it shows panel-lvds { compatible = "hannstar,hsd100pxn1"; backlight = <0x00000031>; power-supply = <0x0000001d>; port { endpoint { remote-endpoint = <0x00000033>; phandle = <0x00000017>; }; }; }; 3) No 'lvds0_out' and 'panel_lvds_in' in __symbols__ node for imx53-qsrb-mcimx-lvds1.dtb, but for imx53-qsrb.dtb they are in it. lvds0_out = "/soc/bus@50000000/ldb@53fa8008/lvds-channel@0/port@2/endpoint"; panel_lvds_in = "/panel-lvds/port/endpoint"; BTW, reverting Saravana's commits 7cb50f6c9fba ("of: property: fw_devlink: Fix stupid bug in remote-endpoint parsing") and/or 7fddac12c382 ("driver core: Fix device_link_flag_is_sync_state_only()") avoids the issue from happening. > >> >> Saravana, DT folks, any ideas? >> >> Thanks. >> >> arch/arm/boot/dts/nxp/imx/Makefile | 4 ++ >> .../boot/dts/nxp/imx/imx53-qsb-common.dtsi | 4 +- >> .../dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso | 43 +++++++++++++++++++ >> 3 files changed, 49 insertions(+), 2 deletions(-) >> create mode 100644 arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso >> >> diff --git a/arch/arm/boot/dts/nxp/imx/Makefile b/arch/arm/boot/dts/nxp/imx/Makefile >> index 92e291603ea1..7116889e1515 100644 >> --- a/arch/arm/boot/dts/nxp/imx/Makefile >> +++ b/arch/arm/boot/dts/nxp/imx/Makefile >> @@ -46,8 +46,10 @@ dtb-$(CONFIG_SOC_IMX53) += \ >> imx53-ppd.dtb \ >> imx53-qsb.dtb \ >> imx53-qsb-hdmi.dtb \ >> + imx53-qsb-mcimx-lvds1.dtb \ >> imx53-qsrb.dtb \ >> imx53-qsrb-hdmi.dtb \ >> + imx53-qsrb-mcimx-lvds1.dtb \ >> imx53-sk-imx53.dtb \ >> imx53-sk-imx53-atm0700d4-lvds.dtb \ >> imx53-sk-imx53-atm0700d4-rgb.dtb \ >> @@ -57,7 +59,9 @@ dtb-$(CONFIG_SOC_IMX53) += \ >> imx53-usbarmory.dtb \ >> imx53-voipac-bsb.dtb >> imx53-qsb-hdmi-dtbs := imx53-qsb.dtb imx53-qsb-hdmi.dtbo >> +imx53-qsb-mcimx-lvds1-dtbs := imx53-qsb.dtb imx53-qsb-mcimx-lvds1.dtbo >> imx53-qsrb-hdmi-dtbs := imx53-qsrb.dtb imx53-qsb-hdmi.dtbo >> +imx53-qsrb-mcimx-lvds1-dtbs := imx53-qsrb.dtb imx53-qsb-mcimx-lvds1.dtbo >> dtb-$(CONFIG_SOC_IMX6Q) += \ >> imx6dl-alti6p.dtb \ >> imx6dl-apf6dev.dtb \ >> diff --git a/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi b/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi >> index 05d7a462ea25..430792a91ccf 100644 >> --- a/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi >> +++ b/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi >> @@ -16,7 +16,7 @@ memory@70000000 { >> <0xb0000000 0x20000000>; >> }; >> >> - backlight_parallel: backlight-parallel { >> + backlight: backlight { > > Nit: this seems unrelated to the LVDS support Do you suggest to do this in a separate patch? If yes, is it worth adding a Fixes tag? > >> compatible = "pwm-backlight"; >> pwms = <&pwm2 0 5000000 0>; >> brightness-levels = <0 4 8 16 32 64 128 255>; >> @@ -89,7 +89,7 @@ panel_dpi: panel { >> compatible = "sii,43wvf1g"; >> pinctrl-names = "default"; >> pinctrl-0 = <&pinctrl_display_power>; >> - backlight = <&backlight_parallel>; >> + backlight = <&backlight>; >> enable-gpios = <&gpio3 24 GPIO_ACTIVE_HIGH>; >> >> port { >> diff --git a/arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso b/arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso >> new file mode 100644 >> index 000000000000..27f6bedf3d39 >> --- /dev/null >> +++ b/arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso >> @@ -0,0 +1,43 @@ >> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) >> +/* >> + * Copyright 2024 NXP >> + */ >> + >> +/dts-v1/; >> +/plugin/; >> + >> +&{/} { >> + panel-lvds { > > Nit: Just 'panel' should be enough. Nope. 'panel-lvds' is needed to differentiate it from 'panel' in imx53-qsb-common.dtsi which is a DPI panel. Using 'panel-lvds', procfs lists exactly the properties needed. root@imx53qsb:~# ls /proc/device-tree/panel-lvds/ backlight compatible name port power-supply Using 'panel', more are listed. root@imx53qsb:~# ls /proc/device-tree/panel/ backlight compatible enable-gpios name phandle pinctrl-0 pinctrl-names port power-supply > >> + compatible = "hannstar,hsd100pxn1"; >> + backlight = <&backlight>; >> + power-supply = <®_3p2v>; >> + >> + port { >> + panel_lvds_in: endpoint { >> + remote-endpoint = <&lvds0_out>; >> + }; >> + }; >> + }; >> +}; >> + >> +&ldb { >> + #address-cells = <1>; >> + #size-cells = <0>; >> + status = "okay"; >> + >> + lvds-channel@0 { >> + #address-cells = <1>; >> + #size-cells = <0>; >> + fsl,data-mapping = "spwg"; >> + fsl,data-width = <18>; >> + status = "okay"; >> + >> + port@2 { >> + reg = <2>; >> + >> + lvds0_out: endpoint { >> + remote-endpoint = <&panel_lvds_in>; >> + }; >> + }; >> + }; >> +}; >> -- >> 2.34.1 >> > -- Regards, Liu Ying
