Bug#996000: general: System does not boot with second monitor attached
Control: Severity -1 normal
Package: general
Severity: important
X-Debbugs-Cc: gaffe_1@live.com
Dear Maintainer,
I installed Debian 11 on a new computer (with a single monitor during installation, connected with HDMI).
Installation went well, but the monitor came up with a very limited resolution (1024x768, I think).
That isn't surprising, the installer (DI) will try and use only a minimum set of possible configurations, in order to function with most hardware it encounters
After a bit of googling, I found that the drivers for the Intel graphics on this board (Rocket Lake, UHD 750) were not
included in the 5.10 kernel that came with Debian Bullseye. I installed kernel 5.14 from Debian Testing, and that seemed to
solve the issue - I got full resolution (still with a single monitor attached).
Ack that sounds about right to me too: AFAICT Rocket Lake, UHD 750 is not yet officially supported in the linux kernel; i915 series has a generic driver, but not with full support for all devices in the series
this is perhaps a bit too new, and you may have to wait a while for the kernel drivers to arrive. [0]
Taking the system into use as my main system, I set it up with two monitors, one connected with an HDMI cable, one with a
DVI cable. (Both monitors are Benq 24 inch 1920x1080.)
Booting the system, it hangs during boot, with a message "VMC (outside TXT) disabled by bios".
This is stating that that you haven't enabled 'Intel virtualization technology' - this should have no effect on the graphic driver support, you would need to enable this if you want to run Virtual Machines.
Booting the system with only the HDMI-connected monitor attached works as expected, the system completes the boot sequence,
I can log in and use the system.
Attaching the second monitor after boot also works, both monitors are recognized and works
As a workaround, I tried enabling "Intel virtualization technology" in the BIOS. Booting with both monitors attached, there
is no longer any error message, but the system still hangs during boot (with a blank screen).
I would expect the system to boot also with two monitors attached.
I would expect this as well - but until there is official support in the kernel for your new hardware then I am afraid that you may have to put up with only connecting the monitor after boot.
Trying newer, back ported kernels, when they become available, is probably your best bet. You could try watching the kernel.org releases looking specifically for the mentions of i915, Rocket Lake, or UHD 750 beforue you try [1]
Very best wishes, and good luck with trying new kernels when they arrive
/Andy
(RattusRattus)
[0] https://gist.github.com/Postrediori/556706b28aff3b831d9e41acb47418c5
[1] https://www.kernel.org/
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