[PATCH v4 0/2] firmware: Avoid coreboot and sysfb to register a pdev for same framebuffer

[Javier Martinez Canillas]

Hello,

This is v4 of a fix to prevent both coreboot and sysfb drivers to register
a platform device to setup a system framebuffer. It has been converted to
a series since contains changes for both drivers, to prevent build issues
on architectures that don't define a global struct screen_info.

Patch #1 adds a sysfb_handles_screen_info() helper that can be used by
drivers to check whether sysfb can use the data set in screen_info or not.

Patch #2 makes the framebuffer_coreboot driver to use that helper to know
if has to setup the system framebuffer or delegate that action to sysfb.

I haven't dropped the collected tags from patch #2 due the logic being
basically the same than in v3.

The patches have only been compiled tested because I don't have access to
a coreboot machine. Please let me know if you plan to merge both patches
through the chrome-platforms tree or if you prefer to get merged through
the drm-misc tree.

Best regards,
Javier

Changes in v4:
- New patch to add sysfb_handles_screen_info() helper (Thomas Zimmermann).
- Use a sysfb_handles_screen_info() helper instead of screen_info_video_type()
  to fix build errors on platforms that don't define a struct screen_info
  (Thomas Zimmermann).

Changes in v3:
- Fix coreboot spelling to be all in lowercase (Julius Werner).

Changes in v2:
- Declare the struct screen_info as constant variable (Thomas Zimmermann).
- Use screen_info_video_type() instead of checking the screen_info video
  types directly (Thomas Zimmermann).
- Fix missing "device" word in a comment (Brian Norris).
- Fix some mispellings in a comment (Brian Norris).
- Change error code returned from -EINVAL to -ENODEV (Brian Norris).

Javier Martinez Canillas (2):
  firmware: sysfb: Add a sysfb_handles_screen_info() helper function
  firmware: coreboot: Don't register a pdev if screen_info data is
    present

 .../firmware/google/framebuffer-coreboot.c    | 14 ++++++++++++++
 drivers/firmware/sysfb.c                      | 19 +++++++++++++++++++
 include/linux/sysfb.h                         |  7 +++++++
 3 files changed, 40 insertions(+)

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2.46.0