drm: Add TODO item for fbdev driver conversion (3c2ed9ce) · Commits · 戴 / test

Documentation/gpu/todo.rst

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	@@ -462,3 +462,30 @@ Contact: Sam Ravnborg

	Outside DRM		Outside DRM
	===========		===========

			Convert fbdev drivers to DRM
			----------------------------

			There are plenty of fbdev drivers for older hardware. Some hwardware has
			become obsolete, but some still provides good(-enough) framebuffers. The
			drivers that are still useful should be converted to DRM and afterwards
			removed from fbdev.

			Very simple fbdev drivers can best be converted by starting with a new
			DRM driver. Simple KMS helpers and SHMEM should be able to handle any
			existing hardware. The new driver's call-back functions are filled from
			existing fbdev code.

			More complex fbdev drivers can be refactored step-by-step into a DRM
			driver with the help of the DRM fbconv helpers. [1] These helpers provide
			the transition layer between the DRM core infrastructure and the fbdev
			driver interface. Create a new DRM driver on top of the fbconv helpers,
			copy over the fbdev driver, and hook it up to the DRM code. Examples for
			several fbdev drivers are available at [1] and a tutorial of this process
			available at [2]. The result is a primitive DRM driver that can run X11
			and Weston.

			- [1] https://gitlab.freedesktop.org/tzimmermann/linux/tree/fbconv
			- [2] https://gitlab.freedesktop.org/tzimmermann/linux/blob/fbconv/drivers/gpu/drm/drm_fbconv_helper.c

			Contact: Thomas Zimmermann <tzimmermann@suse.de>