eDP屏幕适配问题

最新推荐文章于 2025-03-27 20:16:24 发布

liteblue

最新推荐文章于 2025-03-27 20:16:24 发布

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分类专栏： kernel 文章标签：驱动程序

本文链接：https://blog.csdn.net/liteblue/article/details/120418614

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eDP屏幕不显示的原因

屏参确认配置正确后，eDP屏幕不显示
在kernel log搜edp，报这种错

[    5.697505] rockchip-vop ff930000.vop: [drm:vop_crtc_enable] Update mode to 1920x1080p55, type: 14
[    5.911435] rockchip-dp ff970000.dp: AUX CH command reply failed!
[    5.912399] rockchip-dp ff970000.dp: Rx Max Link Rate is abnormal :e8 !
[    5.914310] rockchip-dp ff970000.dp: AUX CH command reply failed!
[    5.914314] rockchip-dp ff970000.dp: LT link start failed!
[    5.914318] rockchip-dp ff970000.dp: eDP link training failed (-110)
[    5.917191] rockchip-dp ff970000.dp: AUX CH command reply failed!
[    5.917194] rockchip-dp ff970000.dp: Rx Max Link Rate is abnormal :0 !
[    5.917197] rockchip-dp ff970000.dp: Rx Max Lane count is abnormal :0 !
[    5.918137] rockchip-dp ff970000.dp: LT link start failed!
[    5.918141] rockchip-dp ff970000.dp: eDP link training failed (-121)
[    5.920190] rockchip-dp ff970000.dp: AUX CH command reply failed!

搜网上资料，发现有两个可能原因：
一是时序问题

https://blog.csdn.net/qq1226176787/article/details/103914430
要求屏端的供电比aux早，可以尝试加长prepare-delay时间到200ms。

二是线的问题

修改

先核对针脚，发现有一对差分线正负接反了
再对时序做优化：

&edp_panel {
	prepare-delay-ms = <210>;
	enable-delay-ms = <210>;
	...
}

这样修改后，eDP屏正常显示了

正常显示了的kernel log

[    5.308069] init: starting service 'bootanim'...
[    5.520952] rockchip-dp ff970000.dp: [drm:analogix_dp_link_start] Enable downspread on the sink
[    5.522385] rockchip-dp ff970000.dp: Link Training Clock Recovery success
[    5.523772] rockchip-dp ff970000.dp: Link Training success!