i.MX ProcessorsのトピックRe: i.MX8M display with EDP panel

i.MX8M display with EDP panel

lizboxy — Thu, 18 Feb 2021 15:55:19 GMT

由于采用i.MX8M要适配多尺寸的屏幕，需要用到EDP屏。

但现在碰到显示的问题：使用dual lane edp 屏幕开机一直显示 No EDID function，

我的设备树如下，附件是SCH，请帮忙确认这是硬件还是软件哪里的问题？能否给点建议？谢谢！

&hdmi {

compatible = "fsl,imx8mq-dp";

lane_mapping = <0xc6>;

fsl,edp; edp_link_rate = <0x6>;

edp_num_lanes = <0x2>;

status = "okay";

};

Re: i.MX8M display with EDP panel

Zhiming_Liu — Fri, 19 Feb 2021 01:34:46 GMT

你的附件还没上传，另外提供一下完整的log

Zhiming

Re: i.MX8M display with EDP panel

lizboxy — Fri, 19 Feb 2021 13:56:06 GMT

请参考附件SCH。

Re: i.MX8M display with EDP panel

lizboxy — Mon, 22 Feb 2021 01:37:36 GMT

目前使用的是5.4.70的内核，设备树如下，打印信息以及原理图如附件，还请建议，谢谢！

/ SPDX-License-Identifier: GPL-2.0

#include "imx8mq-evk.dts"

&irqsteer { status = "okay";

};

&dcss {

status = "okay";

disp-dev = "hdmi_disp";

port@0 {

dcss_out: endpoint {

remote-endpoint = <&hdmi_in>;

};

&hdmi {

compatible = "cdn,imx8mq-dp";

lane-mapping = <0xc6>;

status = "okay";

port@1 {

hdmi_in: endpoint {

remote-endpoint = <&dcss_out>;

};

Re: i.MX8M display with EDP panel

Zhiming_Liu — Mon, 22 Feb 2021 02:15:48 GMT

OK，我在帮你看了

Re: i.MX8M display with EDP panel

Zhiming_Liu — Mon, 22 Feb 2021 03:53:01 GMT

你试一下在UBOOT里设置dp固件

setevn panel dp_fw

saveenv

Re: i.MX8M display with EDP panel

lizboxy — Mon, 22 Feb 2021 07:08:49 GMT

Uboot 输入setenv panel dp_fw

saveenv

仍然不显示，打印消息一样

Re: i.MX8M display with EDP panel

Zhiming_Liu — Tue, 23 Feb 2021 01:26:26 GMT

这可能是固件问题，我在问专家了

Re: i.MX8M display with EDP panel

Zhiming_Liu — Tue, 23 Feb 2021 06:35:53 GMT

你试一下在uboot里添加

"drm.debug=0x7"

系统会进入调试模式，如果不行分享一下log

Re: i.MX8M display with EDP panel

lizboxy — Tue, 23 Feb 2021 07:08:15 GMT

请帮忙看下硬件SCH有没有问题？

Re: i.MX8M display with EDP panel

Zhiming_Liu — Tue, 23 Feb 2021 07:27:58 GMT

硬件没问题

Re: i.MX8M display with EDP panel

lizboxy — Tue, 23 Feb 2021 07:40:09 GMT

"drm.debug=0x7"这句话是添加在Uboot 哪里？

Re: i.MX8M display with EDP panel

Zhiming_Liu — Tue, 23 Feb 2021 07:52:28 GMT

setenv bootargs drm.debug=0x7

saveenv

Re: i.MX8M display with EDP panel

lizboxy — Fri, 26 Feb 2021 14:16:08 GMT

有没有新的进展？

Re: i.MX8M display with EDP panel

Zhiming_Liu — Mon, 01 Mar 2021 01:16:01 GMT

AE那边需要添加drmdebug后的log，你附一下

Re: i.MX8M display with EDP panel

lizboxy — Mon, 01 Mar 2021 04:15:05 GMT

/ SPDX-License-Identifier: GPL-2.0

/*

 * Copyright 2019 NXP.

*/

#include "imx8mq-evk.dts"

&irqsteer {

         status = "okay";

};

&dcss {

         status = "okay";

         disp-dev = "hdmi_disp";

         port@0 {

                 dcss_out: endpoint {

                          remote-endpoint = <&hdmi_in>;

};

};

};

&hdmi {

         compatible = "cdn,imx8mq-dp";

         lane-mapping = <0xc6>;

         status = "okay";

         port@1 {

                 hdmi_in: endpoint {

                          remote-endpoint = <&dcss_out>;

};

};

};

Re: i.MX8M display with EDP panel

lizboxy — Mon, 01 Mar 2021 06:53:47 GMT

Uboot 中添加dp 固件后，可以正常读到EDID，但是还是会报错，请帮忙看看是哪里的问题。

全部log如附件所示，谢谢！

[ 2.441966] imx-dcss 32e00000.display-controller: bound 32c00000.hdmi (ops cdns_mhdp_imx_ops)

[ 2.450801] [drm] Initialized imx-dcss 1.0.0 20190917 for 32e00000.display-controller on minor 0

[ 2.463816] cdns-mhdp-imx 32c00000.hdmi: 0,ff,ff,ff,ff,ff,ff,0

[ 2.478924] cdns-mhdp-imx 32c00000.hdmi: 0,ff,ff,ff,ff,ff,ff,0

[ 2.479094] [drm] Mode: 1920x1080p147800

[ 2.673576] imx-dcss 32e00000.display-controller: Pixel clock set to 147789 kHz instead of 147800 kHz.

[ 2.718677] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_train_link] *ERROR* clock recovery failed

[ 3.194667] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_train_link] *ERROR* training failed: -110

[ 3.194675] cdns-mhdp-imx 32c00000.hdmi: [drm:cdns_mhdp_train_link] *ERROR* Failed to start training -110

[ 3.194684] cdns-mhdp-imx 32c00000.hdmi: [drm:cdn_dp_bridge_enable] *ERROR* Failed link train -110

Re: i.MX8M display with EDP panel

Zhiming_Liu — Tue, 02 Mar 2021 01:49:29 GMT

update:

Seems that HDMI Display port depends on signed_dp_imx8m.bin binary; by default when boot image is generated it includes signed_hdmi_imx8m.bin as default;

Try by using imx-boot-imx8mqevk-sd.bin-flash_dp_evk as boot image

For creating an SD card image using UUU:

uuu -b sd_all imx-boot-imx8mqevk-sd.bin-flash_dp_evk imx-image-multimedia-imx8mqevk.wic.bz2

Re: i.MX8M display with EDP panel

lizboxy — Wed, 03 Mar 2021 00:36:16 GMT

在u-boot里用的就是这个DP固件，或者说这个固件有没有更新？怎样更新？还请建议，谢谢！

另外，

[drm] Mode: 1920x1080p147800；

imx-dcss 32e00000.display-controller: Pixel clock set to 147789 kHz instead of 147800 kHz.

不是已经读出来是147800了还要用147789去代替147800

Re: i.MX8M display with EDP panel

lizboxy — Wed, 03 Mar 2021 13:58:15 GMT

这个是否跟目前用的屏幕是2 lane 有关？内核默认是4 lane的DP。

有看到其他人报一样的错，但他们是4lane 可以正常工作，而2lane 会报错。

https://community.nxp.com/t5/i-MX-Processors/imx8mq-Dual-Lane-DisplayPort/m-p/1043148#M153614

是否就是这个问题？如果是，如何修改？谢谢！