Black screen, UI lock up, when starting Xserver,

[John Talbut]

On 14/09/18 19:54, Adam Jackson wrote:
> On Fri, 2018-09-14 at 18:46 +0100, John Talbut wrote:
>> Thanks Adam
>>
>> If I boot to runlevel 3, log into tty1 as root and run 'X -retro' the UI
>> locks up.
> 
> When this happens, does VT switch still work? Can you hit control-alt-
> backspace to terminate the server? 

No, if I run 'X -retro' from tty1 as root the screen goes black apart
from a steady underscore top left and the keyboard is unresponsive, or
at least nothing changes on the screen when I press any keys.

>If yes (and the answer to both
> should be the same) then the server is "alive" but something about
> changing the video mode has gone awry, so that where the server is
> drawing is not where the hardware is looking.
> 
> This would probably be a kernel bug, probably in the gma500 driver,
> which is not a great place to be as the driver is essentially
> unmaintained afaik. dri-devel at lists.freedesktop.org would be the most
> likely place to find help, and they would probably want to see dmesg
> from a boot with 'drm.debug=0x7' on the kernel command line for the
> details of the attempted modeset, but I wouldn't get my hopes up.

Would anything have changed recently with this driver?  The computer was
working fine until late July.
> 
> Alternatively, you can try booting with 'nomodeset' on the kernel
> command line, which should disable the gma500 driver. X will then use
> the vesa driver, which is normally not a great place to be either, but
> the gma500 driver's only real advantage over vesa is hotplug support as
> neither one has any hardware acceleration.
> 
>> If I boot to runlevel 3, log into tty2 as a user and run 'X -retro' the
>> tty stays live and I get some messages:
> 
> This is just the security checks in the server preventing you from
> running it as a regular user (on the theory that, if anyone on the
> system could start a display server, you could spoof an existing
> session).
> 
>> It is a bit difficult to send whole log files as I do not have an email
>> client on the machine without the desktop.
> 
> If you can ssh in, you can scp files out...
> 
> - ajax
> 
>