[Nouveau] Quadro 4000 with iiyama B2783QSU should be 2560x1440 but detected as 1920x1080.

[Ilia Mirkin]

I think you want the reduced blanking modeline:

$ cvt -r 2560 1440
# 2560x1440 59.95 Hz (CVT 3.69M9-R) hsync: 88.79 kHz; pclk: 241.50 MHz
Modeline "2560x1440R"  241.50  2560 2608 2640 2720  1440 1443 1448
1481 +hsync -vsync

This matches your monitor's detailed timings:

[    55.220] (II) NOUVEAU(0): Supported detailed timing:
[    55.220] (II) NOUVEAU(0): clock: 241.5 MHz   Image Size:  597 x 336 mm
[    55.220] (II) NOUVEAU(0): h_active: 2560  h_sync: 2608  h_sync_end
2640 h_blank_end 2720 h_border: 0
[    55.220] (II) NOUVEAU(0): v_active: 1440  v_sync: 1443  v_sync_end
1448 v_blanking: 1481 v_border: 0

Not sure why a 2560x1440 modeline isn't being advertised in EDID -
perhaps the monitor is in some "safe" setting where that's not
reported? Might have to flip it into DP 1.2 mode or something.

On Wed, Sep 21, 2016 at 10:09 AM, Roger Price <roger at rogerprice.org> wrote:
> Hi, Distribution: openSUSE 42.2 Beta, Kernel: 4.4.  The box is a Dell
> Precision T7500 with an nVidia Quadro 4000 card and a displayport connected
> iiyama B2783QSU 2560x1440 monitor identified as DP-1.
>
> Problem: The monitor is detected as 1920x1080 and not 2560x1440.  See Xorg
> log file at http://rogerprice.org/Xorg.0.log .  There is no file
> /etc/X11/xorg.conf and in the directory /etc/X11/Xorg.conf.d/ the files
> 50-device.conf, 50-monitor.conf and 50-screen.conf contain comments only.
>
> My attempted repair failed:
>
> I used gtf to calculate a 2560x1440_60 mode line
>
>   Modeline "2560x1440_60.00"  311.83  2560 2744 3024 3488  1440 1441 1444
> 1490  -HSync +Vsync
>
> and I then used commands
>
>   xrandr --newmode 2560x1440   311.83  2560 2744 3024 3488  1440 1441 1444
> 1490  -HSync +Vsync
>   xrandr --addmode DP-1 2560x1440
>   xrandr --output DP-1 --mode 2560x1440
>
> The result is that windows on the screen seem to increase in size slightly
> and flow off the screen.  The system tray normally at the bottom of the
> screen has disappeared.  More precisely, command xrandr -q reports:
>
>   Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
>   DVI-I-1 disconnected (normal left inverted right x axis y axis)
>   DP-1 connected 2560x1440+0+0 (normal left inverted right x axis y axis)
> 597mm x 336mm
>     1920x1200     59.95
>     1920x1080     60.00
>     1600x1200     60.00
>     1680x1050     59.88
>     1600x1000     60.01
>     1600x900      60.00
>     1280x1024     75.02
>     1440x900      59.90
>     1024x768      75.03    60.00
>     800x600       75.00    60.32
>     640x480       75.00    59.94
>     2560x1440     60.00*
>   DP-2 disconnected (normal left inverted right x axis y axis)
>
> but command xvidtune -show reports:
>
>   "1920x1200"   154.00   1920 1968 2000 2080   1200 1203 1209 1235 +hsync
> -vsync
>
> I'm not sure if I'm looking at a bug or if this is just noob confusion. Any
> advice or suggestion would be much appreciated.
>
> Roger
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