On Wed, Sep 06, 2023 at 06:26:16PM +0300, Tony Lindgren wrote: > * Marc Haber <mh+linux-kernel@xxxxxxxxxxxx> [230906 14:41]: > > With my tools I have found out that it really seems to be related to the > > CPU of the host. I have changed my VM definition to "copy host CPU > > configuration to VM" in libvirt and have moved this very VM (image and > > settings) to hosts with a "Ryzen 5 Pro 4650G" and to an "Intel Xeon > > E3-1246" where they work flawlessly, while on both APUs I have available > > ("AMD G-T40E" and "AMD GX-412TC SOC") the regression in 6.5 shows. And > > if I boot other VMs on the APUs with 6.5 the issue comes up. It is a > > clear regression since going back to 4.6's serial code solves the issue > > on the APUs. > > Not sure why the CPU matters here.. Neither am I. > One thing to check is if you have these in your .config: > > CONFIG_SERIAL_CORE=y > CONFIG_SERIAL_CORE_CONSOLE=y That's affirmative. Otherwise, I think that serial console wouldn't work at all, but I get early kernel messages just fine and even at normal speed. > Or do you maybe have CONFIG_SERIAL_CORE=m as loadable module? Negative. Greetings Marc -- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421