4K on RPI4?

[James Gritton]

On 2020-10-28 11:00, Klaus Cucinauomo wrote:
>> Am 28.10.2020 um 05:10 schrieb James Gritton <jamie at gritton.org>:
>> 
>> I'd like to move my desktop to FreeBSD for the first time in some 
>> years, and I have an 8GB RPI4 that's working nicely on CURRENT, except 
>> that Xorg insists that my resolution is 1920x1080.  I've got a nice 
>> 60Hz 4K monitor, so it's kind of a shame to only have a quarter of the 
>> pixels I should have.
>> 
>> How do I convince the X server (or the kernel, or whoever) that it's 
>> OK to give me some 4K output.  And if I can get that going, my next 
>> question will be about 60Hz (when I specify it according to the RPI 
>> instructions, the kernel doesn't fully boot).  But speed is icing on 
>> the cake - I just want those pixels!
> 
> 
> https://www.raspberrypi.org/documentation/configuration/hdmi-config.md


Already read and done - that's the very page I meant when I mentioned 
"the RPI instructions".  I take it this has worked for you?  Would you 
happen to have a configuration I could copy?

I have used their recommendation for 2060p:
  hdmi_drive=1
  hdmi_group=1
  hdmi_mode=95
as well as putting my monitor timings directly into config.txt:
  hdmi_drive=1
  hdmi_group=2
  hdmi_mode=87
  hdmi_timings=3840 1 176 88 296 2160 1 8 10 72 0 0 0 30 0 297000000 3
But in both cases, Xorg remains blithely ignorant of 4K.

Also, I have already added lines to my Xorg config about the monitor 
timings, to no avail.  They worked under Debian (on a RockPro64 I'm 
trying to replace), which is a similar version of Xorg.

- Jamie