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mattyclarkson

Member

Registered: 2014-08-29

Posts: 8

[SOLVED] BDM4350UC + RX480 cannot get 4K@60

I'm having trouble with getting 4K@60 between a Phillips BDM4350UC and a Power Color RX480.

When the system boots up it goes into an odd setting where it is sorta 4K@30 but the display reports 68kHz scan rate. The display is garbled due to the odd setting. I can also only connect via the single HDMI output of the graphics card once it switches into this mode, none of the 3 DP connectors output anything.

Initially I was extremely confused thinking that I had borked the installation but it was because GRUB (I have a BIOS/GPT setup) was trying to initialise into this weird setting. I set GRUB_GFXMODE=1024x768x32 so that I can see the boot menu but as soon as KMS takes over it ends up in the weird scan rate.

I started thinking that the board wasn't supported but dmesg has no warnings about the card from amdgpu and it correctly identifies the 3 DP connectors, the HDMI connector and the DVI connector. I then thought that the EDID of the screen maybe borked. I've never had an issue with a screen EDID so not really sure what to do here but did get-edid | parse-edid and it doesn't seem to report all the resolutions and mentions that it doesn't support the EDID extension block that the screen has sent back. I'm a bit clueless as where else to start looking, any tips would be appreciated.

I follow mesa development as much as I can but still unsure about the full support of the amdgpu driver so it might be that I'm debugging something that isn't even supported.

Last edited by mattyclarkson (2017-03-08 19:22:04)

Lone_Wolf

Member

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 11,911

Re: [SOLVED] BDM4350UC + RX480 cannot get 4K@60

There have been problems reported with 4k setups and AMD RX480 cards.

Have you tried with the linux-amd-staging kernel ?
It's supposed to have the most advanced version of the amdgpu kernel module, you can find it in lordHeavy's mesa-git repo.

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Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

(A works at time B)  && (time C > time B ) ≠  (A works at time C)

mattyclarkson

Member

Registered: 2014-08-29

Posts: 8

Re: [SOLVED] BDM4350UC + RX480 cannot get 4K@60

Thanks.  I'll try that, thanks for the tip. Repo Link

mattyclarkson

Member

Registered: 2014-08-29

Posts: 8

Re: [SOLVED] BDM4350UC + RX480 cannot get 4K@60

That sorted it out, get 2160p60 through HDMI now. I get a load of DRM/amdgpu errors, any tips on where to report those? I'd really like to get into some DRM development.

What's the the best place to find out when the patches I need will land in mainline?

Lone_Wolf

Member

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 11,911

Re: [SOLVED] BDM4350UC + RX480 cannot get 4K@60

I don't have the answers, but agd5f is the user name of AMD developer Alex Deucher.
Try contacting him.

He does have the same username on phoronix and sourceforge, and can be reached through their message options (if you are registered at them).

An alternative would be to search the mesa git repo , https://cgit.freedesktop.org/mesa/mesa/log/ .
commit messages usually list the email addresses of the author and reviewer.

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Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

(A works at time B)  && (time C > time B ) ≠  (A works at time C)