[v2,0/3] drm/panic: Add a kmsg dump screen

Message

Jocelyn Falempe June 3, 2024, 9:47 a.m. UTC

Add a kmsg option, which will display the last lines of kmsg,
and should be similar to fbcon.
Add a drm.panic_screen module parameter, so you can choose between
the different panic screens available.
Two options currently, but more will be added later:
 * "user": a short message telling the user to reboot the machine.
 * "kmsg": fill the screen with the last lines of kmsg.

You can even change it at runtime by writing to
/sys/module/drm/parameters/panic_screen

Patch 1-2 are the same as https://patchwork.freedesktop.org/series/133963/
and are here to avoid conflicts.

v2:
 * use module parameter instead of Kconfig choice, so it can be changed at
   runtime. (Javier Martinez Canillas)
 * keep fg16/fg24/fg32 as variable name for the blit functions
   (Javier Martinez Canillas)
 * Add drm_panic_is_pixel_fg() to avoid code duplication.
   (Javier Martinez Canillas)

Jocelyn Falempe (3):
  drm/panic: only draw the foreground color in drm_panic_blit()
  drm/panic: Add a set_pixel() callback to drm_scanout_buffer
  drm/panic: Add a kmsg panic screen

 drivers/gpu/drm/Kconfig     |  11 ++
 drivers/gpu/drm/drm_panic.c | 283 +++++++++++++++++++++++++-----------
 include/drm/drm_panic.h     |   9 ++
 3 files changed, 219 insertions(+), 84 deletions(-)


base-commit: 86266829ea755f737762ebda614c59b136c8feac