triple head: xrandr commands ignored

Felix Miata mrmazda at
Fri Apr 28 09:22:25 UTC 2017

Felix Miata composed on 2017-04-27 06:35 (UTC-0400):

> openSUSE Tumbleweed
> kernel 4.10.10
> server 1.19.3
> ATI HD5450 PCIe gfxcard (Cedar)

> During BIOS display, 1920x1080 Dell is blank, the other two in 80x25. When KMS
> kicks in the framebuffers sometimes only two of the three light up, and in
> 1680x1050. Other times all three light up in 1680x1050.

> In Xorg, instead of two beside and one above, all three are mirrors of the lower
> of the three native resolutions:
> left Dell 1920x1080 on HDMI-1
> right Dell 1920x1200 on DVI-I-1
> above Lenovo 1680x1050 on VGA-1

> All three come out 1680x1050.

> Attached Xorg.0.log has these EEs:
> [   262.280] (EE) Failed to load module "ati" (module does not exist, 0)
> [   262.872] (EE) modeset(0): failed to set mode: Invalid argument
> [   263.155] (EE) modeset(0): failed to set mode: Invalid argument
> [   307.296] (EE) modeset(0): failed to set mode: Invalid argument
> [   307.620] (EE) modeset(0): failed to set mode: Invalid argument

> Where's the invalid argument coming from?

> Why aren't the specified modes 1920x1080 and 1920x1200 applied to the displays
> that support them?

> On restart without closing the Konsole sessions, they reopen in the unreachable
> portion of the vertically extended desktop, where I can't move them down without
> knowning the magic keys that allow the keyboard to make the moves. The mouse is
> constrained to the 1680x1050 each monitor actually displays.

> Attachment is full Xorg.0.log plus xrandr, lspci and inxi output, plus the
> xrandr script that should be configuring the layout and specifying the three
> different native display modes.

Same bad things happen using the xf86-video-ati driver instead of modeset(0).
Instead of attaching and waiting on moderation delay due to over-limit email
size, the info and Xorg.0.log are these files:

When I move the HDMI cable from the 1920x1080 Dell to a 1920x1080 Vizio and
reboot, behavior changes. Instead of 3 displays each running 1680x1050, the
1680x1050 display sleeps, the 1920x1080 Vizio is 1920x1080 containing (bottom)
panel and auto-opened Konsole, the 1920x1200 Dell displays the desktop
background but nothing else, the mouse pointer is restricted to the 1920x1080,
and xrandr -q reports the modes the xrandr startup script expects (3 displays
running in their respective native modes) but with a total size of 5760x2250.
"The wise are known for their understanding, and pleasant
words are persuasive." Proverbs 16:21 (New Living Translation)

 Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata  ***

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