[PATCH 12/15] drm/simple-helper: drm_gem_simple_display_pipe_prepare_fb as default

[Sam Ravnborg]

Hi Daniel,

On Tue, Jun 22, 2021 at 06:55:08PM +0200, Daniel Vetter wrote:
> It's tedious to review this all the time, and my audit showed that
> arcpgu actually forgot to set this.
> 
> Make this the default and stop worrying.
> 
> Again I sprinkled WARN_ON_ONCE on top to make sure we don't have
> strange combinations of hooks: cleanup_fb without prepare_fb doesn't
> make sense, and since simpler drivers are all new they better be GEM
> based drivers.
> 
> v2: Warn and bail when it's _not_ a GEM driver (Noralf)
> 
> Cc: Noralf Trønnes <noralf at tronnes.org>
> Acked-by: Noralf Trønnes <noralf at tronnes.org>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: David Airlie <airlied at linux.ie>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> ---
>  drivers/gpu/drm/drm_simple_kms_helper.c | 12 ++++++++++--
>  include/drm/drm_simple_kms_helper.h     |  7 +++++--
>  2 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
> index 0b095a313c44..735f4f34bcc4 100644
> --- a/drivers/gpu/drm/drm_simple_kms_helper.c
> +++ b/drivers/gpu/drm/drm_simple_kms_helper.c
> @@ -9,6 +9,8 @@
>  #include <drm/drm_atomic.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_gem_atomic_helper.h>
>  #include <drm/drm_managed.h>
>  #include <drm/drm_plane_helper.h>
>  #include <drm/drm_probe_helper.h>
> @@ -225,8 +227,14 @@ static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
>  	struct drm_simple_display_pipe *pipe;
>  
>  	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
> -	if (!pipe->funcs || !pipe->funcs->prepare_fb)
> -		return 0;
> +	if (!pipe->funcs || !pipe->funcs->prepare_fb) {
> +		if (WARN_ON_ONCE(!drm_core_check_feature(plane->dev, DRIVER_GEM)))
> +			return 0;
> +
> +		WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
> +
> +		return drm_gem_simple_display_pipe_prepare_fb(pipe, state);
> +	}
>  
>  	return pipe->funcs->prepare_fb(pipe, state);
>  }
> diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
> index ef9944e9c5fc..363a9a8c3587 100644
> --- a/include/drm/drm_simple_kms_helper.h
> +++ b/include/drm/drm_simple_kms_helper.h
> @@ -116,8 +116,11 @@ struct drm_simple_display_pipe_funcs {
>  	 * the documentation for the &drm_plane_helper_funcs.prepare_fb hook for
>  	 * more details.
>  	 *
> -	 * Drivers which always have their buffers pinned should use
> -	 * drm_gem_simple_display_pipe_prepare_fb() for this hook.
> +	 * For GEM drivers who neither have a @prepare_fb not @cleanup_fb hook
> +	 * set drm_gem_simple_display_pipe_prepare_fb() is called automatically
> +	 * to implement this.
Same comments like before.

	Sam

         * Other drivers which need additional plane
> +	 * processing can call drm_gem_simple_display_pipe_prepare_fb() from
> +	 * their @prepare_fb hook.
>  	 */
>  	int (*prepare_fb)(struct drm_simple_display_pipe *pipe,
>  			  struct drm_plane_state *plane_state);
> -- 
> 2.32.0.rc2