android14 rk628H hdmi转lvds概率性黑屏问题

在rk android14上面调了一款rk628H hdmi转lvds的板子，现在测试发现点屏的时候，开机会概率性的出现黑屏不显示的问题。

出现黑屏的时候，休眠唤醒发现有时可以亮，有时也亮不了。抓取了log，对比正常时和不正常时的log，发现clk上有些差异，但是多测试几遍，发现有时正常的时候，也和不正常时的clk一模一样。

bash 复制代码

[    3.530194][    T8] rk628 9-0050: hdmirx driver version: 0.1.0
[    3.530746][    T8] rk628 9-0050: rk628_display_work: hdmirx detect status:0x15
[    3.540269][   T83] usb 1-1: new high-speed USB device number 2 using xhci-hcd
[    3.658402][    T8] rk628 9-0050: tmdsclk_cnt:1555, modetclk_cnt_hs:3, modetclk_cnt_vs:5914,vs:10
[    3.658418][    T8] rk628 9-0050: read wxh:800x1280, total:920x1394, SCDC_REGS1:0x80000f00, cnt:0
[    3.662696][    T8] rk628 9-0050: cnt_num:1000, tmds_cnt:1556, hs_cnt:3, vs_cnt:5914, hofs:28
[    3.662711][    T8] rk628 9-0050: SCDC_REGS1:0x80000f00, act:800x1280, total:920x1394, fps:60, pixclk:77022000
[    3.662724][    T8] rk628 9-0050: hfp:92, hs:5, hbp:23, vfp:78, vs:10, vbp:26, interlace:0
[    3.688453][   T83] usb 1-1: New USB device found, idVendor=1a86, idProduct=8091, bcdDevice=13.10
[    3.688467][   T83] usb 1-1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[    3.688475][   T83] usb 1-1: Product: USB HUB
[    3.735860][   T83] hub 1-1:1.0: USB hub found
[    3.735942][   T83] hub 1-1:1.0: 4 ports detected
[    3.745980][    T8] rk628 9-0050: hdmirx plug in
[    3.745995][    T8] rk628 9-0050: input: 0, output: 0
[    3.746538][    T8] rk628 9-0050: hdmirx success
[    3.748034][    T8] rk628 9-0050: dsp_frame_vst:4  dsp_frame_hst:908
[    3.808267][    T8] rk628 9-0050: adjust cpll to 1155330000Hz
[    3.808281][    T8] rk628 9-0050: src 800x1280 clock:77022
[    3.808292][    T8] rk628 9-0050: dst 800x1280 clock:77022

后面试着换timing参数看能不能解决。原来的timing参数如下：

bash 复制代码

        clock-frequency = <77000000>;
        hactive = <800>;
        vactive = <1280>;
        hback-porch = <24>;
        hfront-porch = <91>;
        vback-porch = <26>;
        vfront-porch = <78>;
        hsync-len = <5>;
        vsync-len = <10>;

换成后面的timing参数后测试没有出现黑屏的情况了：

bash 复制代码

			clock-frequency = <72000000>;
			hactive = <800>;
			vactive = <1280>;
			hback-porch = <24>;
			hfront-porch = <56>;
			vback-porch = <26>;
			vfront-porch = <14>;
			hsync-len = <20>;
			vsync-len = <10>;

原来的timing参数直接用lvds接口点是没有问题的，但是rk628H转出来就不行，这说明这个芯片对参数的要求还是比较苛刻，兼容性没有那么高。