Comment 35 for bug 1434581

No kernel change. Basically changes to /etc/default/grub are used when running update-grub to create the grub configuration. Leaving GRUB_TERM=console commented out causes grub to initialize some higher resolution graphics framebuffer mode. And (not quite sure) it might be that about some point in time this changed to be a higher resolution.

But looking at the two dmesg outputs you posted (possibly you have both kernels installed on the same box, so grub setup is the same in both cases just the newer kernel ends up being slower) shows both vesafb get initialized nearly identical. So right now its hard to say why things go so much slower in the newer kernels. The simple framebuffer imo should not be so much different in how it works. Cannot say why that works faster. simplefb might just be one of them. There is a whole bunch blacklisted in /etc/modprobe.d/blacklist-framebuffer.conf because they tend to cause issues.

One other detail I noticed in the dmesg output was that the newer kernel managed to initialize local ipmi drivers. Not sure how much this is actually needed. As long as its not required to have access to ipmi directly (not lan) one can disable ipmi_si and dev_ipmi can be disabled in /etc/default/openipmi. Just mentioning that since console usually can be accessed via ipmi and maybe there is some kind of interference.