Arch Linux

Vaporeon

Member

Registered: 2015-10-08

Posts: 7

Force default resolution and KMS to 1920x1080@144Hz?

I'm using a 1080p monitor that can run at 144Hz, however for whatever reason the EDID lists 1920x1080@60Hz as the recommended resolution.
Since I'm using AMDGPU with an RX580, this means KMS and all TTYs default to 60 Hz.

X11 is happy to run at 144 Hz, however I'd like TTYs and things using KMS to run at 144 Hz too.
I tried "video=1920x1080@144" in the kernel command line but that just resulted in black screens and endless flickering when not in X11.

Does anyone know how to set this? I gathered I need to dump and edit the EDID but I'm not even sure what value to change.
A Google search brought up endless results of people not having a clue what they were talking about, and people using nVidia cards.

Last edited by Vaporeon (2019-03-19 10:47:28)

Head_on_a_Stick

Member

From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: Force default resolution and KMS to 1920x1080@144Hz?

https://wiki.archlinux.org/index.php/Ke … s_and_EDID?

Disclaimer: I haven't a clue what I'm talking about

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Vaporeon

Member

Registered: 2015-10-08

Posts: 7

Re: Force default resolution and KMS to 1920x1080@144Hz?

I read all that but can't successfully get a 144Hz TTY, it still runs at 60.

Head_on_a_Stick

Member

From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: Force default resolution and KMS to 1920x1080@144Hz?

What did you try, exactly?

If you post your method then perhaps we can see if you made a mistake.

See also https://bbs.archlinux.org/viewtopic.php?id=57855

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Vaporeon

Member

Registered: 2015-10-08

Posts: 7

Re: Force default resolution and KMS to 1920x1080@144Hz?

Adding video=HDMI-A-2:1920x1080@144 to the kernel commandline.
There seems to be nothing in the kernel log that suggests it failed, the monitor just did not take to it and would not display anything outside X11.

I missed the part to create a EDID from scratch so I'll do that now

Vaporeon

Member

Registered: 2015-10-08

Posts: 7

Re: Force default resolution and KMS to 1920x1080@144Hz?

It seems it can't find the file, if I use either drm_kms_helper.edid_firmware or drm.edid_firmware
The path is correct.

[drm:drm_load_edid_firmware [drm]] *ERROR* Requesting EDID firmware "edid/144h.bin" failed (err=-2)

Head_on_a_Stick

Member

From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: Force default resolution and KMS to 1920x1080@144Hz?

Are you using early KMS?

If so, did you add the custom EDID to the initramfs?

EDIT: you should probably tell us exactly how you created the custom EDID file.

Last edited by Head_on_a_Stick (2019-03-19 15:21:46)

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Vaporeon

Member

Registered: 2015-10-08

Posts: 7

Re: Force default resolution and KMS to 1920x1080@144Hz?

Oh yeah I am. Adding the edid to the initramfs fixed problems with loading it and the reported native resolution is now 1920x1080@144 Hz, however I still get the exact same issues as using the video= argument.

I tried both a new edid made by editing the linux source for building edids, and also tried editing a dump of the real edid to make 144 Hz default.
Both worked in making 144Hz default however neither would work properly in a TTY.

One thing I did notice in xorg logs when running "cat /var/log/Xorg.0.log | grep -i clock" was

[     4.921] (WW) EDID timing clock 325.08 exceeds claimed max 305MHz, fixing
[     4.921] (II) AMDGPU(0): clock: 148.5 MHz   Image Size:  544 x 303 mm
[     4.921] (II) AMDGPU(0): clock: 325.1 MHz   Image Size:  544 x 303 mm
[     4.921] (II) AMDGPU(0): Ranges: V min: 30 V max: 146 Hz, H min: 30 H max: 160 kHz, PixClock max 326 MHz
[     4.921] (II) AMDGPU(0): clock: 285.5 MHz   Image Size:  544 x 303 mm
[     4.921] (II) AMDGPU(0): clock: 235.5 MHz   Image Size:  544 x 303 mm
[     4.921] (II) AMDGPU(0): clock: 88.8 MHz   Image Size:  544 x 303 mm
[     4.921] (II) AMDGPU(0): clock: 119.0 MHz   Image Size:  544 x 303 mm
[    11.520] (WW) EDID timing clock 325.08 exceeds claimed max 305MHz, fixing
[    11.778] (WW) EDID timing clock 325.08 exceeds claimed max 305MHz, fixing
[    11.788] (WW) EDID timing clock 325.08 exceeds claimed max 305MHz, fixing
[   333.519] (WW) EDID timing clock 325.08 exceeds claimed max 305MHz, fixing

This is wrong, the max pixel clock for this monitor is 330MHz.

Vaporeon

Member

Registered: 2015-10-08

Posts: 7

Re: Force default resolution and KMS to 1920x1080@144Hz?

Got the edited EDID dump to work by using Display Port instead, now everything defaults to 144Hz and is stable.

Resolved but also not resolved because I don't know where that bogus 305MHz limit is coming from and you *can* do 144Hz on HDMI2 so there is something strange happening there.

All I did was change the order of two extended blocks so 144Hz was first, would it be safe to just flash that back to the monitor and not worry about kernel workarounds any more?

Last edited by Vaporeon (2019-03-20 12:46:50)