Bug 75223

Summary: 3840x2160 HDMI 30Hz fails on XFX r7-240a-clh4 and r7-250a-lzh4
Product: DRI Reporter: Adam J. Richter <adam_richter2004>
Component: DRM/RadeonAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED FIXED QA Contact:
Severity: normal    
Priority: medium    
Version: XOrg git   
Hardware: x86 (IA32)   
OS: Linux (All)   
i915 platform: i915 features:
Description Flags
tar file containing /var/log/Xorg.0.log and logs of dmesg, xrandr, xrandr --verbose for both cards (r7-240 and r7-250)
possible fix none

Description Adam J. Richter 2014-02-19 18:47:30 UTC
Created attachment 94377 [details]
tar file containing /var/log/Xorg.0.log and logs of dmesg, xrandr, xrandr --verbose for both cards (r7-240 and r7-250)

The XFX Radeon r7-240a-clh4 and XFX Radeon r7-250a-zlh4 video cards do not seem to be able to generate 3840x2160 @ 30 Hz video modes over HDMI, even though I believe their hardware is supposed to be capable of this (~299 MHz pixel clock).

At least with my se39uy04 39" Seiki television, the Radeon X.org driver happily passed through the five 3840x2160 @ 24-30 Hz that the television's advertises in its EDID modes to xrandr, meaning that driver thinks it can support those video modes, but, if I select any of them, the telvision just says "mode not support."  In comparison, if I make a custom video mode for 3840x2160 @ 15Hz, the 4k TV displays that fine.

I am attaching a .tar.gz file containting /var/log/Xorg.0.log and logs of dmesg, xrandr, xrandr --verbose for both cards (r7-240 and r7-250).

Thanks to Alex Deucher for advising me to file this bug report here.

Thanks in advance for any further processing of this bug report.
Comment 1 Alex Deucher 2014-03-06 23:13:22 UTC
Created attachment 95261 [details] [review]
possible fix

Does the attached patch help?
Comment 2 Adam J. Richter 2014-03-07 08:28:15 UTC
I confirm that applying your patch to linux-3.13.0 resulted in both XFX Radeon video cards working (r7-240a-clh4 and r7-250a-zlh4).

Thank you, Alex!  Great work!
Comment 3 Adam J. Richter 2014-03-07 08:29:59 UTC
Just to clarify, I confirm that that patch made both video cards successfully output 3840x2160 over HDMI to a Seiki se39uy04 television.
Comment 4 Alex Deucher 2014-03-07 14:07:17 UTC
Great.  Patch is sent upstream and should show up in the stable series as well soon.

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