[Nouveau] 640x480 does not fill screen

[Dan Espen]

Ilia Mirkin <imirkin at alum.mit.edu> writes:

> On Wed, Feb 6, 2019 at 3:28 PM Dan Espen <dan1espen at gmail.com> wrote:
>>
>> Ilia Mirkin <imirkin at alum.mit.edu> writes:
>>
>> > It would be useful to know how the screen is connected. Also please
>> > grab the monitor's EDID from /sys/class/drm/cardN-connector/edid and
>> > attach it here. It would also be interesting to get a boot with
>> > "drm.debug=0x1e nouveau.debug=disp=trace" which has the modeswitch in
>> > question.
>>
>> The screen is connected using the MDP port.
>> I don't find any cardN-connector directory,
>> the closest match is:
>>
>> /sys/class/drm/card0-DP-1/edid
>
> N = 0
> connector = DP-1
>
> so looks like you found it.
>
> I was actually looking for dmesg with those boot parameters, not the Xorg log.
>
> Something to randomly try -- xrandr -s 640x480 -r 75 -- perhaps it'll
> like that mode better.

Using "-r 75" fixes the problem.

> Also does 720x480 work better?

Yes, 720x480 works without the -r parameter.

> Looking at your EDID, you have:
>
> Established timings supported:
>   720x400 at 70Hz 9:5 HorFreq: 31469 Hz Clock: 28.320 MHz
>   640x480 at 60Hz 4:3 HorFreq: 31469 Hz Clock: 25.175 MHz
>   640x480 at 75Hz 4:3 HorFreq: 37500 Hz Clock: 31.500 MHz
>   800x600 at 60Hz 4:3 HorFreq: 37900 Hz Clock: 40.000 MHz
>   800x600 at 75Hz 4:3 HorFreq: 46900 Hz Clock: 49.500 MHz
>   1024x768 at 60Hz 4:3 HorFreq: 48400 Hz Clock: 65.000 MHz
>   1024x768 at 75Hz 4:3 HorFreq: 60000 Hz Clock: 78.750 MHz
>   1280x1024 at 75Hz 5:4 HorFreq: 80000 Hz Clock: 135.000 MHz
> Standard timings supported:
>   1920x1080 at 60Hz 16:9
>   1600x1200 at 60Hz 4:3 HorFreq: 75000 Hz Clock: 162.000 MHz
>   1280x1024 at 60Hz 5:4 HorFreq: 64000 Hz Clock: 108.000 MHz
>   1280x800 at 60Hz 16:10
>   1152x864 at 75Hz 4:3 HorFreq: 67500 Hz Clock: 108.000 MHz
>
> CTA extension block
> Extension version: 3
> 25 bytes of CTA data
>   Video data block
> ...
>     VIC   3 720x480 at 60Hz 16:9  HorFreq: 31469 Hz Clock: 27.000 MHz
>     VIC   2 720x480 at 60Hz 4:3  HorFreq: 31469 Hz Clock: 27.000 MHz
>     VIC   1 640x480 at 60Hz 4:3  HorFreq: 31469 Hz Clock: 25.175 MHz

Okay, if I read all that right the EDID supports 640x480 at 60 and 75hz.
The monitor acts strangely at 60hz but is okay at 75hz. 
Is this something I should configure or can nouveau figure out the best mode?

-- 
Dan Espen