On 16/09/2023 15:09, nerdopolis wrote:
On Friday, September 15, 2023 4:28:20 AM EDT Jocelyn Falempe wrote:
This introduces a new drm panic handler, which displays a message when a panic
occurs.
So when fbcon is disabled, you can still see a kernel panic.
This is one of the missing feature, when disabling VT/fbcon in the kernel:
https://www.reddit.com/r/linux/comments/10eccv9/config_vtn_in_2023/
Fbcon can be replaced by a userspace kms console, but the panic screen must be
done in the kernel.
This is a proof of concept, and works only with simpledrm, using a new
get_scanout_buffer() api
To test it, make sure you're using the simpledrm driver, and trigger a panic:
echo c > /proc/sysrq-trigger
This seems to work pretty good! With this one, I don't need to have Weston (or
another display server) running for it to work this time.
The panic reason works, which is pretty sweet.
Thanks for testing, that's really appreciated.
FYI: I do get a hunk that fails to apply in simpledrm_remove in
drivers/gpu/drm/tiny/simpledrm.c
Seems to be a change in a recentish commit
https://github.com/torvalds/linux/commit/84e6da7ad5537826343636b846530ec2167d4a19
Thanks for the head-up, when doing this RFC, I'm based on latest
released version v6.5, to avoid having to rebase too often.
When it's closer to merging, I will rebase to drm-misc-next.
Best regards,
--
Jocelyn
