Blank screen after user switching on Intel hw and with KMS on

[Ben Bacarisse]

After starting another X session by swicthing users, attempting to switch back to the first gives a blank screen. If the switch is done using Ctrl+Alt+F7 I can switch to the new user again with Ctrl+Alt+F8; but if I try to switch back using the user switch applet I can't (i.e. both VT7 and VT8 show and blank screen). if I log out of the new user's session, all VTs are blank (incluing 1-6). I can log in using ssh and restating gdm gets everything back to normal.

This seems to be closely realted (but not identical) to some other bugs. The closest being 546578 but (a) I am not using ATI hardware and (b) the problem is not there when KMS is off (i.e. booting with i915.modeset=0 fixes the problem). Just as in 546578, entering a password blind and running xgamma -gamma 1.0 also get the VT back to normal. After this switching back and forth works fine.

I suspect this is just http://bugs.freedesktop.org/show_bug.cgi?id=27382 in another guise but it seems worth reporting.

[Ben Bacarisse (launchpad-bsb)]

I thought I would be able to attach system information using "apport-collect 585498" but (after an authentication exchange) all I get is a message box saying "No additional information collected". If this is considered a new bug that needs full suporting data, please let me know how to provide it.

[Ben Bacarisse (launchpad-bsb)]

Oh dear. I though I was reporting against xorg but that seems to have been changed to xorg-server-vesa and I doubt that has anything to do with the problem. Sorry. I'll try to change that.

[Ben Bacarisse (launchpad-bsb)]

Changed to reflect better the hardware affected, though the problem may not be in XOrg of course.