Re: [9front] displayport thinkpad x230 external monitor black screen

[igor@9lab.org]

I have a TP t420s as well as a x230i connected to an LG Ultrawide
screen at 3440x1440. The following shows the TP t420s:

• https://9lab.org/plan9/thinkpad-t420s/#monitor

The LG Ultrawide works just as well via DP with the TP x230i; here is
my /lib/vgadb entry for the screen:

# LG ULTRAWIDE
lgUW=3440x1440  # 60Hz
	clock=319.75
	shb=3488 ehb=3520 ht=3600
	vrs=1443 vre=1453 vt=1481
	hsync=+ vsync=-

With that entry in place I can use the monitor on the x230i as
follows:

% @{rfork n; aux/realemu; aux/vga -m lgUW  -l '3440x1440'}

… with a resolution of 3440x1440.


Quoth Romano <unobe@cpan.org>:
> I have a TP x230 that has a displayport and vga socket.  I have an
> adapter from vga-to-hdmi (wиth а USB dongle for power) that works with
> an ultrawide LG, but the largest mode via VGA is 1920x1080.  Using the
> displayport to connect to the monitor shows a 2560x1080 mode, along
> with the same modes that are shown with the VGA adapter.  However,
> when trying to use any mode with the displayport directly, I just get
> a black screen.  I ran 'cat /dev/vgactl' "blind", when using the
> ultrawide LG external monitor to see if that yielded anything
> interesting, but didn't see it.  I then switched back to built-in LCD
> screen to capture the rc output, which I've attached to the end of this
> message.
> 
> I reviewed the log for changes to igfx to see if I could pin down the commit
> that might be related, and the best I could come up with is 
>   6f63752d84254b470322fc028dce1c79f7443e3b
> back in May 2017 (almost 6 years ago). I reverted
> /sys/src/9/pc/vgaigfx.c to that commit to see
> if it would build, but unsurprisingly, it does not:
> 
> vgaigfx.c:18 structure not fully declared Pcidev
> vgaigfx.c:68 structure not fully declared Pcidev
> warning: vgaigfx.c:61 used and not set: gtt 
> vgaigfx.c:92 structure not fully declared Pcidev
> vgaigfx.c:92 structure not fully declared Pcidev
> vgaigfx.c:95 structure not fully declared Pcidev
> vgaigfx.c:95 structure not fully declared Pcidev
> vgaigfx.c:161 structure not fully declared Pcidev
> vgaigfx.c:214 name not declared: arrow
> 
> Before go any further, I thought I'd ask on the list: has anyone had
> something similar happen, or know of where the problem might be?
> 
> # --- rc output when connecting to external monitor ---
> cpu% whatis modes
> fn modes {
> 	@ {
> 		rfork n; aux/realemu; aux/vga -m igfx -p
> 	}
> }
> cpu% modes
> ...
> edid mfr            LGD
> edid serialstr      
> edid name           
> edid product        728
> edid serial         0
> edid version        1.3
> edid mfrdate        2012.0
> edid size (cm)      28x16
> edid gamma          2.20
> edid vert (Hz)      0-0
> edid horz (Hz)      0-0
> edid pclkmax        0
> edid flags           digital standby suspend activeoff
> edid 1366x768@60Hz  
> 		clock=75.2
> 		shb=1414 ehb=1478 ht=1582
> 		vrs=772 vre=779 vt=792
> 		hsync=+ vsync=- 
> edid mfr            GSM
> edid serialstr      
> edid name           LG ULTRAWIDE
> edid product        23026
> edid serial         256914
> edid version        1.4
> edid mfrdate        2021.6
> edid size (cm)      80x34
> edid gamma          2.20
> edid vert (Hz)      56-75
> edid horz (Hz)      30000-90000
> edid pclkmax        240000000
> edid flags           digital standby
> edid 2560x1080@60Hz 
> 		clock=185.58
> 		shb=2624 ehb=2688 ht=2784
> 		vrs=1083 vre=1093 vt=1111
> 		hsync=- vsync=- 
> edid 1920x1080@60Hz 
> 		clock=148.5
> 		shb=2008 ehb=2052 ht=2200
> 		vrs=1084 vre=1089 vt=1125
> 		hsync=+ vsync=- 
> edid 640x480@60Hz   
> 		clock=25.175
> 		shb=656 ehb=752 ht=800
> 		vrs=490 vre=492 vt=525
> 		hsync=- vsync=- 
> edid 640x480@75Hz   
> 		clock=31.5
> 		shb=656 ehb=720 ht=840
> 		vrs=481 vre=484 vt=500
> 		hsync=- vsync=- 
> edid 800x600@60Hz   
> 		clock=40
> 		shb=840 ehb=968 ht=1056
> 		vrs=601 vre=605 vt=628
> 		hsync=+ vsync=+ 
> edid 800x600@75Hz   
> 		clock=49.5
> 		shb=816 ehb=896 ht=1056
> 		vrs=601 vre=604 vt=625
> 		hsync=+ vsync=+ 
> edid 1024x768@60Hz  
> 		clock=65
> 		shb=1048 ehb=1184 ht=1344
> 		vrs=771 vre=777 vt=806
> 		hsync=- vsync=- 
> edid 1024x768@75Hz  
> 		clock=78.75
> 		shb=1040 ehb=1136 ht=1312
> 		vrs=769 vre=772 vt=800
> 		hsync=+ vsync=+ 
> edid 1280x1024@75Hz 
> 		clock=135
> 		shb=1296 ehb=1440 ht=1688
> 		vrs=1025 vre=1028 vt=1066
> 		hsync=+ vsync=+ 
> cpu% whatis lcd
> fn lcd {
> 	@ {
> 		rfork n; aux/realemu; aux/vga -m igfx -l 1366x768
> 	}
> }
> cpu% whatis lg
> fn lg {
> 	@ {
> 		rfork n; aux/realemu; aux/vga -m igfx -l 1920x1080
> 	}
> }
> cpu% cat /dev/vgactl
> type igfx
> size 1376x768x32 x8r8g8b8
> actualsize 1366x768
> tilt none
> hwgc igfxhwgc
> hwaccel off
> hwblank on
> addr p 0xe0000000 v 0xfffffe80e0000000 size 0x4000000
> softscreen on
> cpu% lg
> cpu% cat /dev/vgactl
> type igfx
> size 1920x1080x32 x8r8g8b8
> tilt none
> hwgc igfxhwgc
> hwaccel off
> hwblank on
> addr p 0xe0000000 v 0xfffffe80e0000000 size 0x4000000
> softscreen on
> cpu% lcd
> cpu%
>