Bug 20409 - xdpyinfo reports incorrect DPI under dual screen
Summary: xdpyinfo reports incorrect DPI under dual screen
Status: RESOLVED DUPLICATE of bug 25615
Alias: None
Product: xorg
Classification: Unclassified
Component: * Other (show other bugs)
Version: 7.4 (2008.09)
Hardware: All All
: high normal
Assignee: Luc Verhaegen
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-03-01 07:40 UTC by Elmar Stellnberger
Modified: 2009-12-21 13:13 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
/var/log/Xorg.0.log (56.88 KB, text/plain)
2009-12-21 12:34 UTC, Elmar Stellnberger
no flags Details

Description Elmar Stellnberger 2009-03-01 07:40:20 UTC
> xdpyinfo | egrep "resolution|dimension"
  dimensions:    3840x1200 pixels (555x350 millimeters)
  resolution:    176x87 dots per inch
This is very nasty since programs like KWord which rely on xdpyinfo do not work at all.

> xrandr -q|egrep "Screen| connected"
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 3840 x 1200
DVI-D_1 connected 1920x1200+1920+0 550mm x 344mm
PANEL connected 1920x1200+0+0 508mm x 317mm

> grep DisplaySize /etc/X11/xorg.conf
        DisplaySize  370 230
        DisplaySize  555 350
PANEL in deed: 370mm x 230mm

xdpyinfo should perhaps return the dpi value for the primary screen featuring 555x350mm:
3.4 x 3.4 dpmm =  87 x 87 dpi  (555 350)
5.1 x 5.2 dpmm = 132 x 133 dpi (370 230)

Consequently I would expect the following output:
> xdpyinfo | egrep "resolution"
  resolution:    87x87 dots per inch
and not:
  resolution:    176x87 dots per inch
Comment 1 Alan Coopersmith 2009-03-02 09:57:39 UTC
xdpyinfo can only report what the X server tells it, so if the
wrong numbers are reported, they're coming from the X server.
Comment 2 Elmar Stellnberger 2009-03-02 11:06:24 UTC
Sure and KWord accesses the library functions directly rather than executing xdpyinfo. Just didn't know which library to assign the bug to. So DDX/xorg is the right component.
Comment 3 Elmar Stellnberger 2009-03-24 02:15:22 UTC
screen #0:
  print screen:    no
  dimensions:    3840x1200 pixels (555x350 millimeters)
  resolution:    87x87 dots per inch
...

resolved for
X.Org X Server 1.5.2,
xorg-x11-server-7.4-17.4.1
Comment 4 Elmar Stellnberger 2009-09-06 03:37:46 UTC
Too bad!
  After a while this having worked well it is now again impossible to edit texts with kword in Xinerama mode. Even worse, Xinerama mode can not be switched off due to Bug 22452.

xdpyinfo | grep --after 5 "screen #"
screen #0:
  print screen:    no
  dimensions:    3840x1200 pixels (555x350 millimeters)
  resolution:    176x87 dots per inch
  depths (7):    24, 1, 4, 8, 15, 16, 32
  root window id:    0x153


should be: 87x87 dots as discussed above.

  Please re-fix this as soon as possible!
Comment 5 Elmar Stellnberger 2009-09-06 03:39:03 UTC
applies to xorg-x11-driver-video-radeonhd-1.2.5_20090506_4be5f71-7.16.
Comment 6 Yang Zhao 2009-09-06 12:09:44 UTC
Attach your xorg.conf and Xorg.0.log please.
Comment 7 Elmar Stellnberger 2009-11-18 09:03:29 UTC
resolved again for xorg-x11-driver-video-radeonhd-1.3.0_20091106_619706-2.1.x86_64 after an intermittent fallback to the old error.
Comment 8 Elmar Stellnberger 2009-12-13 03:48:12 UTC
BOOOO !
fallback for xorg-x11-driver-video-radeonhd-1.3.0_20091124_6387ab4-4.1.x86_64.
Comment 9 Yang Zhao 2009-12-13 10:16:21 UTC
Log please.
Comment 10 Elmar Stellnberger 2009-12-15 03:58:43 UTC
OOps; Sorry. It only applies to the radeon driver, not to radeonhd by time (although they say there it would be an error of Xorg rather than of radeon).
Comment 11 Yang Zhao 2009-12-15 07:42:20 UTC
Well, I certainly can't reproduce it here with dual monitor with identical dimensions.

Probably a bug in the server that crops up when running dual screen using monitors that have different dimensions.  The inconsistencies in affected version alone says this probably isn't a driver issue.
Comment 12 Elmar Stellnberger 2009-12-21 11:57:43 UTC
  Still here for identical monitors in dual screen setup. The error appears very frequent but not always:

> xdpyinfo | egrep "resolution"
  resolution:    176x87 dots per inch

xorg-x11-driver-video-radeonhd-1.3.0_20091124_6387ab4-4.1.x86_64
Comment 13 Yang Zhao 2009-12-21 12:08:20 UTC
(In reply to comment #12)
>   Still here for identical monitors in dual screen setup. The error appears
> very frequent but not always:
> 
> > xdpyinfo | egrep "resolution"
>   resolution:    176x87 dots per inch

Attach a complete Xorg.0.log. An output fragment is useless for diagnostics, since it's already been said the issue is not reproducible here.
Comment 14 Elmar Stellnberger 2009-12-21 12:22:34 UTC
 This is already the full Xorg.0.log as in place. You will have to dig into the sources if you don`t find anything in the logs.
Comment 15 Yang Zhao 2009-12-21 12:31:43 UTC
I don't see any logs attached to this bug or in any of the comments.

Each issue being tracked should be self-contained, unless there's an obvious dependency on another.
Comment 16 Elmar Stellnberger 2009-12-21 12:34:59 UTC
Created attachment 32226 [details]
/var/log/Xorg.0.log

oops; must have posted log to another bug (don`t know which one).
Comment 17 Alan Coopersmith 2009-12-21 12:42:44 UTC
(In reply to comment #16)
> oops; must have posted log to another bug (don`t know which one).

Bug 25615
Comment 18 Yang Zhao 2009-12-21 13:01:59 UTC
The physical dimensions of the displays involved are clearly non-identical.  The original resolution stands.  As it's been repeated elsewhere, this is not a driver bug.

*** This bug has been marked as a duplicate of bug 25615 ***
Comment 19 Elmar Stellnberger 2009-12-21 13:04:44 UTC
Please reassign correctly so that we can push forward a solution.
Comment 20 Elmar Stellnberger 2009-12-21 13:05:53 UTC
each bug a duplicate of the other lol (that does not save us from reassigning).
Comment 21 Elmar Stellnberger 2009-12-21 13:07:18 UTC
.
Comment 22 Alan Coopersmith 2009-12-21 13:13:47 UTC
Try reading your bug mail more carefully - this bug was closed as duplicate
of the still open generic X server bug 25615.

*** This bug has been marked as a duplicate of bug 25615 ***


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