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。
[ 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：
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：
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。