Kernel internal error with DART-MX8M-PLUS DSI with Raspberry PI display

[user38572]

Hello everyone,

I am trying to get a Raspberry PI 7" display (dsi display with internal tc358762 dsi to dpi converter and microcontroller for initialization and backlight control) to work on a custom board with a DART-MX8M-PLUS (i.MX 8M Plus) on it, however I cannot get it to work. The device tree is based on the imx8mp-var-dart-dt8mcustomboard.dts file from https://github.com/varigit/linux-imx/. Below are the relevant changes made to this file to try and get the display to work (the full file is bigger):

// More stuff here

/ {
    // More stuff here
    
	panel@1 {
	    reg = <1>;
		compatible = "qiaodian,qd43003c0-40";
		//compatible = "raspberrypi,7inch-dsi";
		power-supply = <&attiny>;
		backlight = <&attiny>;

		port {
			panel_in: endpoint {
				remote-endpoint = <&bridge_out>;
			};
		};
	};
};

&lcdif1 {
	status = "okay";
};

&mipi_dsi {
	#address-cells = <1>;
	#size-cells = <0>;
	status = "okay";

	bridge@0 {
		compatible = "toshiba,tc358762";
		reg = <0>;
		vddc-supply = <&attiny>;

		ports {
			#address-cells = <1>;
			#size-cells = <0>;

			port@0 {
				reg = <0>;

				bridge_in: endpoint {
					remote-endpoint = <&dsi_out>;
				};
			};

			port@1 {
				reg = <1>;

				bridge_out: endpoint {
					remote-endpoint = <&panel_in>;
				};
			};
		};
	};
	
	port@1 {
		reg = <1>;

		dsi_out: endpoint {
			data-lanes = <1>;
			remote-endpoint = <&bridge_in>;
		};
	};
};

&i2c6 {
    clock-frequency = <400000>;
	pinctrl-names = "default", "gpio";
	pinctrl-0 = <&pinctrl_i2c6>;
	//pinctrl-1 = <&pinctrl_i2c6_gpio>;
	scl-gpios = <&gpio3 28 GPIO_ACTIVE_HIGH>;
	sda-gpios = <&gpio3 29 GPIO_ACTIVE_HIGH>;
	status = "okay";
	
    #address-cells = <1>;
    #size-cells = <0>;
    
    attiny: regulator@45 {
		compatible = "raspberrypi,7inch-touchscreen-panel-regulator";
		reg = <0x45>;
	};
};

// More stuff here

Without these changes the board boots fine. With these changes I receive the following internal error during boot (only relevant part of boot log shown):

[    2.079254] gpio-144 (scl): enforced open drain please flag it properly in DT/ACPI DSDT/board file
[    2.089639] OF: graph: no port node found in /soc@0/bus@30800000/i2c@30a30000/ov5640_mipi@3c
[    2.098111] ov5640 1-003c: endpoint node not found
[    2.102914] ov5640: probe of 1-003c failed with error -22
[    2.108373] i2c i2c-1: IMX I2C adapter registered
[    2.113625] gpio-92 (scl): enforced open drain please flag it properly in DT/ACPI DSDT/board file
[    2.123483] imx_sec_dsim_drv 32e60000.mipi_dsi: Failed to create device link (0x180) with 5-0045
[    2.187563] imx_sec_dsim_drv 32e60000.mipi_dsi: Failed to create device link (0x180) with 5-0045
[    2.196609] i2c i2c-5: IMX I2C adapter registered
[    2.201763] imx8mq-usb-phy 381f0040.usb-phy: supply vbus not found, using dummy regulator
[    2.210407] imx8mq-usb-phy 382f0040.usb-phy: supply vbus not found, using dummy regulator
[    2.244025] panel-simple 100000003.panel: Specify missing connector_type
[    2.268172] imx-drm display-subsystem: bound imx-lcdifv3-crtc.0 (ops lcdifv3_crtc_ops)
[    2.276236] imx_sec_dsim_drv 32e60000.mipi_dsi: version number is 0x1060200
[    2.283650] imx_sec_dsim_drv 32e60000.mipi_dsi: [drm] *ERROR* modalias failure on /soc@0/bus@32c00000/mipi_dsi@32e60000/port@1
[    2.295091] imx-drm display-subsystem: bound 32e60000.mipi_dsi (ops imx_sec_dsim_ops)
[    2.303817] [drm] Initialized imx-drm 1.0.0 20120507 for display-subsystem on minor 1
[    2.347202] Unable to handle kernel paging request at virtual address fffffffffffffe0b
[    2.355125] Mem abort info:
[    2.357918]   ESR = 0x0000000096000004
[    2.361675]   EC = 0x25: DABT (current EL), IL = 32 bits
[    2.366991]   SET = 0, FnV = 0
[    2.370053]   EA = 0, S1PTW = 0
[    2.373203]   FSC = 0x04: level 0 translation fault
[    2.378090] Data abort info:
[    2.380976]   ISV = 0, ISS = 0x00000004
[    2.384815]   CM = 0, WnR = 0
[    2.387790] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000042097000
[    2.394498] [fffffffffffffe0b] pgd=0000000000000000, p4d=0000000000000000
[    2.401301] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[    2.407569] Modules linked in:
[    2.410627] CPU: 2 PID: 9 Comm: kworker/u8:0 Not tainted 6.1.36-imx8mp+g7248bd964cd9 #1
[    2.418633] Hardware name: Variscite DART-MX8M-PLUS on custom board (DT)
[    2.425335] Workqueue: events_unbound deferred_probe_work_func
[    2.431177] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    2.438146] pc : drm_panel_get_modes+0x44/0xb0
[    2.442595] lr : drm_panel_get_modes+0x44/0xb0
[    2.447041] sp : ffff80000a1fb6a0
[    2.450356] x29: ffff80000a1fb6a0 x28: ffff0000c1566200 x27: 0000000000001000
[    2.457500] x26: 0000000000000023 x25: ffff800009fa64e0 x24: ffff0000c1286000
[    2.464644] x23: 00000000fffffffd x22: ffff0000c1287420 x21: 0000000000000000
[    2.471786] x20: ffff0000c12870a0 x19: fffffffffffffdfb x18: 0000000000000006
[    2.478930] x17: 6f206d6574737973 x16: 6275732d79616c70 x15: ffff80000a1fb1e0
[    2.486077] x14: 0000000000000000 x13: ffff800009ed2198 x12: 00000000000004bf
[    2.493219] x11: 0000000000000195 x10: ffff800009f2a198 x9 : ffff800009ed2198
[    2.500361] x8 : 00000000ffffefff x7 : ffff800009f2a198 x6 : 80000000fffff000
[    2.507505] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000
[    2.514648] x2 : 0000000000000000 x1 : ffff0000c00c0000 x0 : 0000000000000021
[    2.521794] Call trace:
[    2.524241]  drm_panel_get_modes+0x44/0xb0
[    2.528344]  sec_mipi_dsim_connector_get_modes+0x58/0x74
[    2.533663]  drm_helper_probe_single_connector_modes+0x1c4/0x510
[    2.539673]  drm_client_modeset_probe+0x204/0x1190
[    2.544472]  __drm_fb_helper_initial_config_and_unlock+0x44/0x540
[    2.550572]  drm_fbdev_client_hotplug+0x150/0x210
[    2.555282]  drm_fbdev_generic_setup+0xb4/0x194
[    2.559818]  imx_drm_bind+0x260/0x2e0
[    2.563484]  try_to_bring_up_aggregate_device+0x1dc/0x2d0
[    2.568891]  __component_add+0xa4/0x190
[    2.572735]  component_add+0x14/0x20
[    2.576315]  lcdifv3_crtc_probe+0x50/0xb0
[    2.580333]  platform_probe+0x68/0xc0
[    2.584000]  really_probe+0xc0/0x3dc
[    2.587583]  __driver_probe_device+0x7c/0x160
[    2.591947]  driver_probe_device+0x3c/0x110
[    2.596137]  __device_attach_driver+0xbc/0x160
[    2.600588]  bus_for_each_drv+0x7c/0xd4
[    2.604431]  __device_attach+0x9c/0x1c0
[    2.608274]  device_initial_probe+0x14/0x20
[    2.612464]  bus_probe_device+0x9c/0xa4
[    2.616307]  deferred_probe_work_func+0x94/0xe4
[    2.620841]  process_one_work+0x1d4/0x330
[    2.624857]  worker_thread+0x220/0x430
[    2.628613]  kthread+0x108/0x10c
[    2.631844]  ret_from_fork+0x10/0x20
[    2.635428] Code: aa1303e1 f0002d80 91338000 97ffd87b (f9400a61)
[    2.641524] ---[ end trace 0000000000000000 ]---
[    3.711705] Hot alarm is canceled. GPU3D clock will return to 64/64

The display initialization works and the backlight comes on when I remove the panel and dsi parts from the device tree and leave only the attiny bit in the i2c port. Additionally I can see from the warning in the log that the panel driver loads.

I suspect this error could be a bug in the IMX DRM driver.

I have tried both linux kernel version 6.6.52 and 6.1.36. Both kernels come from the previously linked imx-linux github.

Does anyone have any clue what could be wrong?

Thanks!

[Chavira]

HI @user38572!

Thank you for contacting NXP Support!

Can you try with this device tree?

Only you have to add the driver of the panel that you will use.

also You can refer to this device tree

// More stuff here

/ {
    // More stuff here
    
	panel {
		compatible = "";
		power-supply = <&attiny>;
		backlight = <&attiny>;

		port {
			panel_in: endpoint {
				remote-endpoint = <&bridge_out>;
			};
		};
	};
};

&lcdif1 {
	status = "okay";
};

&mipi_dsi {
	#address-cells = <1>;
	#size-cells = <0>;
	status = "okay";

	bridge@0 {
		compatible = "toshiba,tc358762";
		reg = <0>;
		vddc-supply = <&attiny>;

		ports {
			#address-cells = <1>;
			#size-cells = <0>;

			port@0 {
				reg = <0>;

				bridge_in: endpoint {
					remote-endpoint = <&dsi_out>;
				};
			};

			port@1 {
				reg = <1>;

				bridge_out: endpoint {
					remote-endpoint = <&panel_in>;
				};
			};
		};
	};
	
	ports {
		#address-cells = <1>;
		#size-cells = <0>;

		port@1 {
			reg = <1>;

			dsi_out: endpoint {
				data-lanes = <1 2>;
				remote-endpoint = <&bridge_in>;
			};
		};
	};
};

&i2c6 {
    clock-frequency = <400000>;
	pinctrl-names = "default", "gpio";
	pinctrl-0 = <&pinctrl_i2c6>;
	//pinctrl-1 = <&pinctrl_i2c6_gpio>;
	scl-gpios = <&gpio3 28 GPIO_ACTIVE_HIGH>;
	sda-gpios = <&gpio3 29 GPIO_ACTIVE_HIGH>;
	status = "okay";
	
    #address-cells = <1>;
    #size-cells = <0>;
    
    attiny: regulator@45 {
		compatible = "raspberrypi,7inch-touchscreen-panel-regulator";
		reg = <0x45>;
	};
};

// More stuff here

Unfortunately we don't have the board and that BSP is modified by Variscite if the proposed modification doesn't work please contact to Variscite Support.

Best Regards!

Chavira

[user38572]

Thank you for your reply. Unfortunately it does not solve the problem. With the device tree you suggested the system does boot but the display never shows. I believe the lcdif driver gets deferred infinitely. I suspect this is due to the ports declaration in the device tree overriding port 0 which connects to the lcdif.

The other device tree you linked I have seen before and the device tree I originally wrote is based off of it.

Do you perhaps have any other suggestions that might work?

Thanks!