Bug 312951

Summary:	Wrong default resolution selected for screen LVDS
Product:	[Plasma] KScreen	Reporter:	Steven Franzen <sfranzen85>
Component:	common	Assignee:	Alex Fiestas <afiestas>
Status:	RESOLVED FIXED
Severity:	normal	CC:	dvratil
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:	http://commits.kde.org/libkscreen/b309874669283054825f24194bdafff1e776a0ce	Version Fixed In:
Sentry Crash Report:
Attachments:	kscreen-console output xrandr --verbose output

Description Steven Franzen 2013-01-09 15:17:21 UTC

Created attachment 76337 [details]
kscreen-console output

My laptop has a 16:9 LCD screen ("LVDS") with native resolution 1366x768, but KScreen has marked 640x480 as the "Preferred mode" (see attachment). 

KScreen selected this resolution upon my first use, but also for each new KDE session, forgetting my manual changes to the resolution.

This is perhaps related to bug 312944 and/or to fglrx. I use this driver because its performance is a bit better than the FOSS drivers for me, but I do remember having issues with the LCD's EDID information in the past. According to kscreen-console and xrandr --verbose, the EDID info is "unavailable" for the laptop panel but not for the external screen. However, it does look like EDID sections are listed for both screens in /var/log/Xorg.0.log.

Comment 1 Daniel Vrátil 2013-01-09 15:51:18 UTC

IIRC we've already seen EDID being available only to root user (therefore X sees it, but not user in xrandr --verbose) - need to investigate a bit.

Could you please provide output of xrandr --verbose? The "preferred mode" is not exactly what I thought it was and it causes KCM and KDED to misbehave sometimes (like in this case :-) )

Comment 2 Steven Franzen 2013-01-09 16:09:01 UTC

Created attachment 76340 [details]
xrandr --verbose output

Output of xrandr, showing EDID for external screen "CRT1" but not for LVDS.

Comment 3 Lamarque V. Souza 2013-01-09 21:18:55 UTC

Git commit b309874669283054825f24194bdafff1e776a0ce by Lamarque V. Souza.
Committed on 09/01/2013 at 22:07.
Pushed by lvsouza into branch 'master'.

Semantic change in XRandROutput::edid() and select the first preferred mode
found for a montior.

REVIEW: 107940
Related: bug 312236

M  +7    -1    backends/xrandr/xrandroutput.cpp

http://commits.kde.org/libkscreen/b309874669283054825f24194bdafff1e776a0ce