desktop-packages team mailing list archive

[Hadmut Danisch <hadmut@xxxxxxxxxx>]

Public bug reported:

Today, there are two sorts of computer monitors with digital input
(mostly HDMI) available:

The ones designed to be used with computers. They report a list of
supported resolutions where the highest resolution is the physical
resolution of the panel. Since X11 always picks the highest resolution
it can work with (or the first in the list), it usually picks the
correct resolution matching the physical panel.

And then there are the ones designed for TV and video. These devices
usually report a standard set of default video resolutions, such as
1920x1080, 1280x720, and so on, even if the listed resolutions (or the
preferred) is higher than that of the panel. This causes X11/Ubuntu to
pick a higher resolution than the panel has. This works with displaying
movies, but not a computer desktop. Characters become unreadable, lines
invisible, and everything is blurred. It is important to choose a
resolution matching the physical resolution of the panel.


This can be easily with xrandr, e.g. 
xrandr -s 1280x720

Earlier versions of gdm had a init directory, where shellscripts to be
run could be put. Putting xrandr in a shell script in this directory
simply fixed the problem.

But with lightdm I could not find a way to run such a command.

Thus, ubuntu with ligthdm cannot be used with displays of the second
kind, i.e. all TV/Video monitors, although they use similar panels and
could be used with Linux perfectly.

Where could I put this command to have it run by lightdm after starting
the X server but before generating the login greeter?

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: lightdm 0.9.3-0ubuntu6
ProcVersionSignature: Ubuntu 3.0.0-9.13-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
Architecture: amd64
Date: Wed Aug 24 14:21:41 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110802.1)
ProcEnviron:
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: lightdm (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug oneiric

-- 
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https://bugs.launchpad.net/bugs/832720

Title:
  screen resolution cannot be set with lightdm

Status in “lightdm” package in Ubuntu:
  New

Bug description:
  Today, there are two sorts of computer monitors with digital input
  (mostly HDMI) available:

  The ones designed to be used with computers. They report a list of
  supported resolutions where the highest resolution is the physical
  resolution of the panel. Since X11 always picks the highest resolution
  it can work with (or the first in the list), it usually picks the
  correct resolution matching the physical panel.

  And then there are the ones designed for TV and video. These devices
  usually report a standard set of default video resolutions, such as
  1920x1080, 1280x720, and so on, even if the listed resolutions (or the
  preferred) is higher than that of the panel. This causes X11/Ubuntu to
  pick a higher resolution than the panel has. This works with
  displaying movies, but not a computer desktop. Characters become
  unreadable, lines invisible, and everything is blurred. It is
  important to choose a resolution matching the physical resolution of
  the panel.

  
  This can be easily with xrandr, e.g. 
  xrandr -s 1280x720

  Earlier versions of gdm had a init directory, where shellscripts to be
  run could be put. Putting xrandr in a shell script in this directory
  simply fixed the problem.

  But with lightdm I could not find a way to run such a command.

  Thus, ubuntu with ligthdm cannot be used with displays of the second
  kind, i.e. all TV/Video monitors, although they use similar panels and
  could be used with Linux perfectly.

  Where could I put this command to have it run by lightdm after
  starting the X server but before generating the login greeter?

  ProblemType: Bug
  DistroRelease: Ubuntu 11.10
  Package: lightdm 0.9.3-0ubuntu6
  ProcVersionSignature: Ubuntu 3.0.0-9.13-generic 3.0.3
  Uname: Linux 3.0.0-9-generic x86_64
  Architecture: amd64
  Date: Wed Aug 24 14:21:41 2011
  InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110802.1)
  ProcEnviron:
   LANG=de_DE.UTF-8
   SHELL=/bin/bash
  SourcePackage: lightdm
  UpgradeStatus: No upgrade log present (probably fresh install)

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