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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - Radeon Trinity 7400G fails with 4K UHD screen - atombios stuck executing BF64"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91197#c11">Comment # 11</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - Radeon Trinity 7400G fails with 4K UHD screen - atombios stuck executing BF64"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91197">bug 91197</a>
from <span class="vcard"><a class="email" href="mailto:dennis.jansen@web.de" title="dennis.jansen@web.de">dennis.jansen@web.de</a>
</span></b>
<pre>I've found a workaround:
xrandr --newmode "3840x2160_30" 262.92 3840 3888 3920 4000 2160 2163 2168
2191 +hsync
xrandr --addmode HDMI-0 "3840x2160_30"
xrandr --output HDMI-0 --mode 3840x2160_30
I'm guessing the pixel clock might have been too high. Same problem with the
Windows driver. The page (<a href="http://www.epanorama.net/faq/vga2rgb/calc.html">http://www.epanorama.net/faq/vga2rgb/calc.html</a>)
allowed me to convert the modeline with lower clock created with cru
(<a href="http://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU">http://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU</a>) in
Windows to Linux. I was pleasantly surprised to find even vdpau working well,
of course only up to FullHD video, but smooth playback on 4k resolution.</pre>
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