drm: Rely on mode_config data for fb_helper initialization

Instead of receiving the num_crts as a parameter, we can read it
directly from the mode_config structure.  I audited the drivers that
invoke this helper and I believe all of them initialize the mode_config
struct accordingly, prior to calling the fb_helper.

I used the following coccinelle hack to make this transformation, except
for the function headers and comment updates.  The first and second
rules are split because I couldn't find a way to remove the unused
temporary variables at the same time I removed the parameter.

// <smpl>
@r@
expression A,B,D,E;
identifier C;
@@
(
- drm_fb_helper_init(A,B,C,D)
+ drm_fb_helper_init(A,B,D)
|
- drm_fbdev_cma_init_with_funcs(A,B,C,D,E)
+ drm_fbdev_cma_init_with_funcs(A,B,D,E)
|
- drm_fbdev_cma_init(A,B,C,D)
+ drm_fbdev_cma_init(A,B,D)
)

@@
expression A,B,C,D,E;
@@
(
- drm_fb_helper_init(A,B,C,D)
+ drm_fb_helper_init(A,B,D)
|
- drm_fbdev_cma_init_with_funcs(A,B,C,D,E)
+ drm_fbdev_cma_init_with_funcs(A,B,D,E)
|
- drm_fbdev_cma_init(A,B,C,D)
+ drm_fbdev_cma_init(A,B,D)
)

@@
identifier r.C;
type T;
expression V;
@@
- T C;
<...
when != C
- C = V;
...>
// </smpl>

Changes since v1:
 - Rebased on top of the tip of drm-misc-next.
 - Remove mention to sti since a proper fix got merged.

Suggested-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170202162640.27261-1-krisman@collabora.co.uk

2 files changed, 4 insertions, 6 deletions

diff --git a/include/drm/drm_fb_cma_helper.h b/include/drm/drm_fb_cma_helper.h
index 8dd6e5585e51..a5ecc0a58260 100644
--- a/include/drm/drm_fb_cma_helper.h
+++ b/include/drm/drm_fb_cma_helper.h
@@ -16,11 +16,10 @@ struct drm_plane;
 struct drm_plane_state;
 
 struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev,
-	unsigned int preferred_bpp, unsigned int num_crtc,
-	unsigned int max_conn_count, const struct drm_framebuffer_funcs *funcs);
+	unsigned int preferred_bpp, unsigned int max_conn_count,
+	const struct drm_framebuffer_funcs *funcs);
 struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
-	unsigned int preferred_bpp, unsigned int num_crtc,
-	unsigned int max_conn_count);
+	unsigned int preferred_bpp, unsigned int max_conn_count);
 void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma);
 
 void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma);
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index e62e1cf22678..278820ee17ad 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -236,8 +236,7 @@ struct drm_fb_helper {
 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 			   const struct drm_fb_helper_funcs *funcs);
 int drm_fb_helper_init(struct drm_device *dev,
-		       struct drm_fb_helper *helper, int crtc_count,
-		       int max_conn);
+		       struct drm_fb_helper *helper, int max_conn);
 void drm_fb_helper_fini(struct drm_fb_helper *helper);
 int drm_fb_helper_blank(int blank, struct fb_info *info);
 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,