[PATCH 1/2] drm/todo: Convert drivers to generic fbdev emulation

[Noralf Trønnes]

Den 29.10.2019 08.06, skrev Thomas Zimmermann:
> This replaces the orignal TODO item for drm_fb_helper_fbdev_setup() and
> _teardown(), which are deprecated.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>  Documentation/gpu/todo.rst | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
> index 6792fa9b6b6b..4aa767461e0e 100644
> --- a/Documentation/gpu/todo.rst
> +++ b/Documentation/gpu/todo.rst
> @@ -171,10 +171,10 @@ Contact: Maintainer of the driver you plan to convert
>  
>  Level: Intermediate
>  
> -Convert drivers to use drm_fb_helper_fbdev_setup/teardown()
> ------------------------------------------------------------
> +Convert drivers to use drm_fbdev_generic_setup()
> +------------------------------------------------
>  
> -Most drivers can use drm_fb_helper_fbdev_setup() except maybe:
> +Most drivers can use drm_fbdev_generic_setup() except maybe:
>  
>  - amdgpu which has special logic to decide whether to call
>    drm_helper_disable_unused_functions()
> @@ -184,8 +184,10 @@ Most drivers can use drm_fb_helper_fbdev_setup() except maybe:
>  
>  - i915 which calls drm_fb_helper_initial_config() in a worker
>  
> -Drivers that use drm_framebuffer_remove() to clean up the fbdev framebuffer can
> -probably use drm_fb_helper_fbdev_teardown().
> +Current generic fbdev emulation expects the framebuffer in system
> +memory (or system-like memory). This might be a problem for certain
> +drivers. Generic fbdev emulation should have a way of operating on
> +I/O memory.
>  
>  Contact: Maintainer of the driver you plan to convert
>  

I think you can just delete the entire _setup/_teardown entry including
the list of drivers. Many more drivers have issues with the generic
emulation so no point in listing individual drivers at this early stage.
You can add that the driver has to be atomic and that it needs to
support prime vmap/mmap. Maybe also the current shadow buffer
performance penalty for shmem backed buffers.

> @@ -328,9 +330,6 @@ drm_fb_helper tasks
>    these igt tests need to be fixed: kms_fbcon_fbt at psr and
>    kms_fbcon_fbt at psr-suspend.
>  
> -- The max connector argument for drm_fb_helper_init() and
> -  drm_fb_helper_fbdev_setup() isn't used anymore and can be removed.
> -

This entry is still valid for drm_fb_helper_init().

Noralf.

>  - The helper doesn't keep an array of connectors anymore so these can be
>    removed: drm_fb_helper_single_add_all_connectors(),
>    drm_fb_helper_add_one_connector() and drm_fb_helper_remove_one_connector().
>