On Wed, 2021-06-30 at 10:15 +0000, Alessio wrote:
[...] the video becomes black with some horizontal lines .
Powering off the system, then on, the screen is ok.
I used to see this quite frequently with my Debian install (Daniel
Thompson's installer and kernel) To me it looks like the video
readout is misconfigured and the framebuffer is smeared vertically, so
the lines you see are the logo and boot spinner.
 linux 5.7.19-30 based on tsys tree
On Wed, 2021-06-30 at 11:36 +0100, Peter Robinson wrote:
I believe it's a bug somewhere in the firmware but I've not had time
to debug it. I suspect basically some device doesn't get reset
properly by the firmware on reboot and so causes issues actually
Certainly sounds like it. Like Eduardo, I worked around by forcing the
system off and then booting from that state.
I only recently installed fedora 34 and I haven't seen the horizontal
lines, but I also have trouble rebooting. The screen blanks, but the
machine seems to hang instead of rebooting, and I have to force it off
by holding down the power key for 5-10 seconds.