[RFC][PATCH] drm: Nuke modifier[1-3]

[Eric Engestrom]

On Wednesday, 2016-11-16 13:33:16 +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> It has been suggested that having per-plane modifiers is making life
> more difficult for userspace, so let's just retire modifier[1-3] and
> use modifier[0] to apply to the entire framebuffer.
> 
> Obviosuly this means that if individual planes need different tiling
> layouts and whatnot we will need a new modifier for each combination
> of planes with different tiling layouts.
> 
> For a bit of extra backwards compatilbilty the kernel will allow
> non-zero modifier[1+] but it require that they will match modifier[0].
> This in case there's existing userspace out there that sets
> modifier[1+] to something non-zero with planar formats.
> 
> Mostly a cocci job, with a bit of manual stuff mixed in.
> 
> @@
> struct drm_framebuffer *fb;
> expression E;
> @@
> - fb->modifier[E]
> + fb->modifier
> 
> @@
> struct drm_framebuffer fb;
> expression E;
> @@
> - fb.modifier[E]
> + fb.modifier
> 
> Cc: Kristian Høgsberg <hoegsberg at gmail.com>
> Cc: Ben Widawsky <benjamin.widawsky at intel.com>
> Cc: Rob Clark <robdclark at gmail.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Tomeu Vizoso <tomeu at tomeuvizoso.net>
> Cc: dczaplejewicz at collabora.co.uk
> Suggested-by: Kristian Høgsberg <hoegsberg at gmail.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_atomic.c              |  2 +-
>  drivers/gpu/drm/drm_framebuffer.c         |  7 +++
>  drivers/gpu/drm/drm_modeset_helper.c      |  2 +-
>  drivers/gpu/drm/i915/i915_debugfs.c       |  4 +-
>  drivers/gpu/drm/i915/intel_atomic_plane.c |  4 +-
>  drivers/gpu/drm/i915/intel_display.c      | 72 +++++++++++++++----------------
>  drivers/gpu/drm/i915/intel_fbdev.c        |  2 +-
>  drivers/gpu/drm/i915/intel_pm.c           | 22 +++++-----
>  drivers/gpu/drm/i915/intel_sprite.c       | 14 +++---
>  drivers/gpu/drm/msm/mdp/mdp4/mdp4_plane.c |  2 +-
>  include/drm/drm_framebuffer.h             |  4 +-
>  include/uapi/drm/drm_mode.h               | 13 +++---
>  12 files changed, 79 insertions(+), 69 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 57e0a6e96f6d..bfaa6e4a9989 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -922,12 +922,12 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
>  
>  		drm_printf(p, "\t\tformat=%s\n",
>  		              drm_get_format_name(fb->pixel_format, &format_name));
> +		drm_printf(p, "\t\t\tmodifier=0x%llx\n", fb->modifier);
>  		drm_printf(p, "\t\tsize=%dx%d\n", fb->width, fb->height);
>  		drm_printf(p, "\t\tlayers:\n");
>  		for (i = 0; i < n; i++) {
>  			drm_printf(p, "\t\t\tpitch[%d]=%u\n", i, fb->pitches[i]);
>  			drm_printf(p, "\t\t\toffset[%d]=%u\n", i, fb->offsets[i]);
> -			drm_printf(p, "\t\t\tmodifier[%d]=0x%llx\n", i, fb->modifier[i]);
>  		}
>  	}
>  	drm_printf(p, "\tcrtc-pos=" DRM_RECT_FMT "\n", DRM_RECT_ARG(&dest));
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 06ad3d1350c4..cbf0c893f426 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -177,6 +177,13 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>  			return -EINVAL;
>  		}
>  
> +		if (r->flags & DRM_MODE_FB_MODIFIERS &&

+		    r->modifier[i] &&

Otherwise this forces the modifiers to be set for all planes, doesn't it?

> +		    r->modifier[i] != r->modifier[0]) {
> +			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
> +				      r->modifier[i], i);
> +			return -EINVAL;
> +		}
> +
>  		/* modifier specific checks: */
>  		switch (r->modifier[i]) {
>  		case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE: