Public bug reported: If you setup a big desktop that spans two monitors, gnome-display- properties is required to add a Virtual line to the subsection "Display" in section "screen" of the xorg.conf as generated by aticonfig. If (at least) the horizontal resolution (maybe the vertical as well) is NOT a multiple of 64, this will render fglrx unable to report the correct resolution of either display to xrandr.
For example, for two displays side-by-side with a physical resolution of 1680x1050 each, gnome-display-properties will insert: Virtual 3360 1050 however, after logging off and on, xrandr will no longer report 1680x1050 as a valid resolution (missing from xrandr -q and consequently in the gnome-display-properties ui) for either display unless you increase the virtual resolution to a multiple of 64: Virtual 3392 3392 This is on a Lenovo ThinkPad T500, using the integrated display and DisplayPort output. Steps to reproduce this: a) initiate xorg.conf using sudo aticonfig --initial (if not done already by fglrx-installer; move your own customized xorg.conf away if present) b) log off and on again, make sure you are running fglrx using fglrxinfo and that xrandr -q reports the correct physical resolution of your integrated/primary display c) connect external/secondary display d) make sure xrandr -q reports correct physical resolution of external display e) go to gnome-display-properties, untick clone mode, put displays side-by-side, apply (or do that using xrandr parameters) d) agree to the suggestion that a Virtual line needs to be added to your xorg.conf to accomodate for the larger desktop area e) log off, log on expected behaviour: gnome-display-properties (or xrandr) should now be able to put the two displays in big/extended desktop mode side-by-side with their corresponding physical resolutions actual behaviour: xrandr does no longer detect the correct physical resolution of either display. ** Affects: fglrx-installer (Ubuntu) Importance: Undecided Status: New ** Description changed: If you setup a big desktop that spans two monitors, gnome-display- properties is required to add a Virtual line to the subsection "Display" in section "screen" of the xorg.conf as generated by aticonfig. If (at least) the horizontal resolution (maybe the vertical as well) is NOT a multiple of 64, this will render fglrx unable to report the correct resolution of either display to xrandr. For example, for two displays side-by-side with a physical resolution of 1680x1050 each, gnome-display-properties will insert: Virtual 3360 1050 however, after logging off and on, xrandr will no longer report 1680x1050 as a valid resolution (missing from xrandr -q and consequently in the gnome-display-properties ui) for either display unless you increase the virtual resolution to a multiple of 64: Virtual 3392 3392 This is on a Lenovo ThinkPad T500, using the integrated display and DisplayPort output. Steps to reproduce this: - a) initiate xorg.conf using sudo aticonfig --initial (if not done already be fglrx-installer; move your own customized xorg.conf away if present) + a) initiate xorg.conf using sudo aticonfig --initial (if not done already by fglrx-installer; move your own customized xorg.conf away if present) b) log off and on again, make sure you are running fglrx using fglrxinfo and that xrandr -q reports the correct physical resolution of your integrated/primary display c) connect external/secondary display d) make sure xrandr -q reports correct physical resolution of external display e) go to gnome-display-properties, untick clone mode, put displays side-by-side, apply (or do that using xrandr parameters) d) agree to the suggestion that a Virtual line needs to be added to your xorg.conf to accomodate for the larger desktop area e) log off, log on expected behaviour: gnome-display-properties (or xrandr) should not be able to put the two displays in big/extended desktop mode side-by-side with their corresponding physical resolutions actual behaviour: xrandr does no longer detect the correct physical resolution of either display. ** Description changed: If you setup a big desktop that spans two monitors, gnome-display- properties is required to add a Virtual line to the subsection "Display" in section "screen" of the xorg.conf as generated by aticonfig. If (at least) the horizontal resolution (maybe the vertical as well) is NOT a multiple of 64, this will render fglrx unable to report the correct resolution of either display to xrandr. For example, for two displays side-by-side with a physical resolution of 1680x1050 each, gnome-display-properties will insert: Virtual 3360 1050 however, after logging off and on, xrandr will no longer report 1680x1050 as a valid resolution (missing from xrandr -q and consequently in the gnome-display-properties ui) for either display unless you increase the virtual resolution to a multiple of 64: Virtual 3392 3392 This is on a Lenovo ThinkPad T500, using the integrated display and DisplayPort output. Steps to reproduce this: a) initiate xorg.conf using sudo aticonfig --initial (if not done already by fglrx-installer; move your own customized xorg.conf away if present) b) log off and on again, make sure you are running fglrx using fglrxinfo and that xrandr -q reports the correct physical resolution of your integrated/primary display c) connect external/secondary display d) make sure xrandr -q reports correct physical resolution of external display e) go to gnome-display-properties, untick clone mode, put displays side-by-side, apply (or do that using xrandr parameters) d) agree to the suggestion that a Virtual line needs to be added to your xorg.conf to accomodate for the larger desktop area e) log off, log on expected behaviour: - gnome-display-properties (or xrandr) should not be able to put the two displays in big/extended desktop mode side-by-side with their corresponding physical resolutions + gnome-display-properties (or xrandr) should now be able to put the two displays in big/extended desktop mode side-by-side with their corresponding physical resolutions actual behaviour: xrandr does no longer detect the correct physical resolution of either display. -- [fglrx] fails to detect correct resolution with non-multiple of 64 virtual desktop area https://bugs.launchpad.net/bugs/659205 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs