Created attachment 24051 [details] [review] Xorg.0.log with repeated switches to 800x600 and back to 1280x1024. When I switch to a resolution below 1024x768, the screen gets blanked and my lcd reports that the incoming signal is out of range. This happens with all radeon and radeonhd drivers which support my Radeon 4670 RV730XT, but only with DVI output, VGA seems ok. It looks like the drivers calculate wrong modes but strangely only at low resolutions. The Option "DefaultTMDSPLL" doesn't help, neither enabled nor disabled.
does turning off coherent mode help? xrandr --output DVI-0 --set coherent_mode 0
On Thu, 19 Mar 2009 14:56:21 -0700 (PDT) bugzilla-daemon@freedesktop.org wrote: > --- Comment #1 from Alex Deucher <agd5f@yahoo.com> 2009-03-19 > 14:56:20 PST --- does turning off coherent mode help? > xrandr --output DVI-0 --set coherent_mode 0 It doesnt seem to make any difference. Logfile says that coherent mode is disabled, the screen gets black for a second and then the lcd again reports "Signal out of range".
Created attachment 24055 [details] Xorg.0.log with disabled coherent mode before, while and after modeswitching
DVI seems to have issues with low dot clocks on DCE 3.2 display engines. I've just changed the driver to use the scaler by default instead: 1ddee7cd6fd267b2fc86f21af27c5425eb0835a4 You can also use the scaler on your current driver as follows: xrandr --output DVI-0 --set scaler <scale type> where scale type is: full or center or aspect.
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