New monitor, pink vertical line and crazy screen resolution with Evergreen + KMS

[Dave Witbrodt]

James Cloos wrote:
>>>>>> "Dave" == Dave Witbrodt <dawitbro at sbcglobal.net> writes:
> 
> Dave> 2) Monitor OSD info still reports 1922x1200, a seemingly impossible video mode!
> 
> Do any of the lines in the log mention 1922?

I believe you are referring to Xorg.0.log here?  If so, DRM + KMS has 
already set the mode by the time the X server runs.  X itself queries 
the monitor, which reports 1920x1200 (among others) as an available mode.

If you are are referring to 'dmesg' output, the only mode info I ever 
see printed there is the FB console setting 240x75 text mode.

In short:

1) Once radeondrmfb kicks in (before X server runs), the monitor's 
onscreen display (using control panel buttons) indicates a bizarre 
1922x1200 display mode.  (Shouldn't the monitor reject that as out of 
range?)

2) X server only indicates (in Xorg.0.log and via 'xrandr -q') that the 
mode is 1920x1200.

KMS is miscommunicating with the monitor when using HDMI (or 
DVI-to-HDMI), setting up a funky 1922x1200 mode.  DRM believes it has 
set up 1920x1200, so is probably reporting that to X.  X reports 
1920x1200, both as a mode detected as supported by the monitor and as 
the mode it is selecting.


> I'm curious whether the modeline is being mis-calculated due to a
> visible vs blanking period vs porch vs sync issue, or pixel freq
> or hfreq rounding issue, or something else of that sort?

Yeah, it reminds of the way CRT displays could be programmed to set up 
nonstandard modes, including stuff that would damage the monitor.  I 
always assumed that LCD displays did not allow nonstandard/unsupported 
modes to be programmed, but at the moment it seems clear that they do. 
(Or this one does.)  The pink (or light purple) vertical line appears to 
be 2 pixels wide, apparently corresponding to the extra 2 pixels in the 
strange 1922 mode reported by the monitor.

Is there a way to get KMS to output graphics resolution info during the 
boot sequence?  Something like a "debug=1" kernel parameter?


Thanks,
Dave W.