Bug 24419

Summary: Acer AL1916W EDID issues
Product: xorg Reporter: Steven Wilson <excyber>
Component: Server/GeneralAssignee: Xorg Project Team <xorg-team>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
radeon Xorg.0.log with no xorg.conf
none
Patch against 1.6.4 to add quirk none

Description Steven Wilson 2009-10-09 06:59:04 UTC 
Created attachment 30219 [details]
radeon Xorg.0.log with no xorg.conf

My Acer AL1916W appears to have some EDID issues that interfere with selecting a sane default mode. At a minimum, it appears that the first detailed timing mode is not flagged as the preferred mode. This mode works fine with radeon (when specified explicitly with a ModeLine and PreferredMode) and with fglrx (which selects it by default). With radeonhd it shows a blank screen.

Both radeon and radeonhd seem to select the 75Hz 1440x900 mode by default; with radeon this shows a blank screen, and with radeonhd the image is unstable. With fglrx this mode seems to be thrown out (not listed by xrandr).

FWIW, an .inf file is attached to https://bugzilla.redhat.com/show_bug.cgi?id=200572
Comment 1 Steven Wilson 2009-10-12 02:48:59 UTC 
Created attachment 30283 [details] [review]
Patch against 1.6.4 to add quirk

I managed to figure out where the relevant quirk is defined and patched it in; seems to work nicely. For whatever reason, radeonhd seems to ignore the quirk (it's in the log, but it still defaults to the 75Hz mode). I made it against 1.6.4, and I'm not 100% sure on the formatting, but I'm happily running without xorg.conf.
Comment 2 Steven Wilson 2010-03-19 21:53:01 UTC 
Closing; this seems to have been squashed sometime in the past few weeks, at least with KMS (which previously exhibited similar behavior). Both Fedora 13 Alpha and Lucid Beta 1 now have the 1440x900 75Hz mode working, whereas Lucid Alpha 3 still had the old behavior.

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