Message-ID: <20160425163816.GF4329@intel.com>
Date:	Mon, 25 Apr 2016 19:38:16 +0300
From:	Ville Syrjälä <ville.syrjala@...ux.intel.com>
To:	Noralf Trønnes <noralf@...nnes.org>,
	linux-fbdev@...r.kernel.org, tomi.valkeinen@...com,
	laurent.pinchart@...asonboard.com, dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/8] drm/rect: Add some drm_clip_rect utility functions

On Mon, Apr 25, 2016 at 06:05:20PM +0200, Daniel Vetter wrote:
> On Mon, Apr 25, 2016 at 06:09:44PM +0300, Ville Syrjälä wrote:
> > On Mon, Apr 25, 2016 at 04:03:13PM +0200, Noralf Trønnes wrote:
> > > 
> > > Den 25.04.2016 15:02, skrev Ville Syrjälä:
> > > > On Mon, Apr 25, 2016 at 02:55:52PM +0200, Noralf Trønnes wrote:
> > > >> Den 25.04.2016 14:39, skrev Ville Syrjälä:
> > > >>> On Sun, Apr 24, 2016 at 10:48:55PM +0200, Noralf Trønnes wrote:
> > > >>>> Add some utility functions for struct drm_clip_rect.
> > > >>> Looks like mostly you're just duplicating the drm_rect stuff. Why can't
> > > >>> you use what's there already?
> > > >> That's because the framebuffer flushing uses drm_clip_rect and not drm_rect:
> > > > Converting to drm_rect is not an option?
> > > 
> > > That's difficult or at least verbose to do because clips is an array.
> > > I could use drm_rect on the calling side (fbdev) since it's only one clip
> > > which the changes are merged into, and then convert it when I call dirty().
> > > But the driver can get zero or more clips from the dirty ioctl so I don't
> > > see a clean way to convert this array to drm_rect without more code than
> > > this proposal has.
> > 
> > Just some kind of simple drm_clip_rect_to_rect() thing should be enough AFAICS.
> 
> Yeah, drm_clip_rect is the uapi struct, drm_rect is the internal one.
> Similar case is drm_display_mode vs. drm_mode_modeinfo. We have
> umode_to_mode and mode_to_umode helpers to deal with that. I do agree that
> it would make sense to switch the internal ->dirty callback over to the
> internal drm_struct. Would need a kmalloc+copy in the dirtyfb ioctl, but
> since the structs actually match in their member names (just not the
> size/signedness, sigh) there shouldn't be any need for driver changes. So
> fairly simple patch.

Or if we want to avoid the malloc, then the merge() thing could just
internally convert one at a time on stack when going through them.
Though then someone might want to do a merge() with internal drm_rects,
and we'd be right where we started. But I'm not sure that will happen,
so perhaps it's just too much future proofing.

> 
> Ofc you need to compile-test all the drivers (at least those using ->dirty
> hook) to make sure gcc is still happy with all the signed vs. unsigned
> stuff. Maybe that turns up something, but hopefully not.
> 
> Sorry for that late request, but I really didn't realize what's going on
> here :(
> -Daniel
> 
> > 
> > > 
> > > Here's the driver side:
> > > 
> > > static int mipi_dbi_dirtyfb(struct drm_framebuffer *fb, void *vmem,
> > >                  unsigned flags, unsigned color,
> > >                  struct drm_clip_rect *clips, unsigned num_clips)
> > > {
> > >      struct tinydrm_device *tdev = fb->dev->dev_private;
> > >      struct lcdreg *reg = tdev->lcdreg;
> > >      struct drm_clip_rect full_clip = {
> > >          .x1 = 0,
> > >          .x2 = fb->width,
> > >          .y1 = 0,
> > >          .y2 = fb->height,
> > >      };
> > >      struct drm_clip_rect clip;
> > >      int ret;
> > > 
> > >      drm_clip_rect_reset(&clip);
> > >      drm_clip_rect_merge(&clip, clips, num_clips, flags,
> > >                  fb->width, fb->height);
> > >      if (!drm_clip_rect_intersect(&clip, &full_clip)) {
> > >          DRM_DEBUG_KMS("Empty clip\n");
> > >          return -EINVAL;
> > >      }
> > > [...]
> > 
> > > 
> > > >> struct drm_framebuffer_funcs {
> > > >> [...]
> > > >>           int (*dirty)(struct drm_framebuffer *framebuffer,
> > > >>                        struct drm_file *file_priv, unsigned flags,
> > > >>                        unsigned color, struct drm_clip_rect *clips,
> > > >>                        unsigned num_clips);
> > > >> };
> > > >>
> > > >>>> Signed-off-by: Noralf Trønnes <noralf@...nnes.org>
> > > >>>> ---
> > > >>>>    drivers/gpu/drm/drm_rect.c | 67 ++++++++++++++++++++++++++++++++++++++++++++
> > > >>>>    include/drm/drm_rect.h     | 69 ++++++++++++++++++++++++++++++++++++++++++++++
> > > >>>>    2 files changed, 136 insertions(+)
> > > >>>>
> > > >>>> diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> > > >>>> index a8e2c86..a9fb1a8 100644
> > > >>>> --- a/drivers/gpu/drm/drm_rect.c
> > > >>>> +++ b/drivers/gpu/drm/drm_rect.c
> > > >>>> @@ -434,3 +434,70 @@ void drm_rect_rotate_inv(struct drm_rect *r,
> > > >>>>    	}
> > > >>>>    }
> > > >>>>    EXPORT_SYMBOL(drm_rect_rotate_inv);
> > > >>>> +
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_intersect - intersect two clip rectangles
> > > >>>> + * @r1: first clip rectangle
> > > >>>> + * @r2: second clip rectangle
> > > >>>> + *
> > > >>>> + * Calculate the intersection of clip rectangles @r1 and @r2.
> > > >>>> + * @r1 will be overwritten with the intersection.
> > > >>>> + *
> > > >>>> + * RETURNS:
> > > >>>> + * %true if rectangle @r1 is still visible after the operation,
> > > >>>> + * %false otherwise.
> > > >>>> + */
> > > >>>> +bool drm_clip_rect_intersect(struct drm_clip_rect *r1,
> > > >>>> +			     const struct drm_clip_rect *r2)
> > > >>>> +{
> > > >>>> +	r1->x1 = max(r1->x1, r2->x1);
> > > >>>> +	r1->y1 = max(r1->y1, r2->y1);
> > > >>>> +	r1->x2 = min(r1->x2, r2->x2);
> > > >>>> +	r1->y2 = min(r1->y2, r2->y2);
> > > >>>> +
> > > >>>> +	return drm_clip_rect_visible(r1);
> > > >>>> +}
> > > >>>> +EXPORT_SYMBOL(drm_clip_rect_intersect);
> > > >>>> +
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_merge - Merge clip rectangles
> > > >>>> + * @dst: destination clip rectangle
> > > >>>> + * @src: source clip rectangle(s), can be NULL
> > > >>>> + * @num_clips: number of source clip rectangles
> > > >>>> + * @flags: drm_mode_fb_dirty_cmd flags (DRM_MODE_FB_DIRTY_ANNOTATE_COPY)
> > > >>>> + * @width: width of clip rectangle if @src is NULL
> > > >>>> + * @height: height of clip rectangle if @src is NULL
> > > >>>> + *
> > > >>>> + * The dirtyfb ioctl allows for a NULL clip rectangle to be passed in,
> > > >>>> + * so if @src is NULL, width and height is used to set a full clip rectangle.
> > > >>>> + * @dst takes part in the merge unless it is empty {0,0,0,0}.
> > > >>>> + */
> > > >>>> +void drm_clip_rect_merge(struct drm_clip_rect *dst,
> > > >>>> +			 struct drm_clip_rect *src, unsigned num_clips,
> > > >>>> +			 unsigned flags, u32 width, u32 height)
> > > >>>> +{
> > > >>>> +	int i;
> > > >>>> +
> > > >>>> +	if (!src || !num_clips) {
> > > >>>> +		dst->x1 = 0;
> > > >>>> +		dst->x2 = width;
> > > >>>> +		dst->y1 = 0;
> > > >>>> +		dst->y2 = height;
> > > >>>> +		return;
> > > >>>> +	}
> > > >>>> +
> > > >>>> +	if (drm_clip_rect_is_empty(dst)) {
> > > >>>> +		dst->x1 = ~0;
> > > >>>> +		dst->y1 = ~0;
> > > >>>> +	}
> > > >>>> +
> > > >>>> +	for (i = 0; i < num_clips; i++) {
> > > >>>> +		if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY)
> > > >>>> +			i++;
> > > >>>> +		dst->x1 = min(dst->x1, src[i].x1);
> > > >>>> +		dst->x2 = max(dst->x2, src[i].x2);
> > > >>>> +		dst->y1 = min(dst->y1, src[i].y1);
> > > >>>> +		dst->y2 = max(dst->y2, src[i].y2);
> > > >>>> +	}
> > > >>>> +}
> > > >>>> +EXPORT_SYMBOL(drm_clip_rect_merge);
> > > >>>> diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> > > >>>> index 83bb156..936ad8d 100644
> > > >>>> --- a/include/drm/drm_rect.h
> > > >>>> +++ b/include/drm/drm_rect.h
> > > >>>> @@ -24,6 +24,8 @@
> > > >>>>    #ifndef DRM_RECT_H
> > > >>>>    #define DRM_RECT_H
> > > >>>>    
> > > >>>> +#include <uapi/drm/drm.h>
> > > >>>> +
> > > >>>>    /**
> > > >>>>     * DOC: rect utils
> > > >>>>     *
> > > >>>> @@ -171,4 +173,71 @@ void drm_rect_rotate_inv(struct drm_rect *r,
> > > >>>>    			 int width, int height,
> > > >>>>    			 unsigned int rotation);
> > > >>>>    
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_width - determine the clip rectangle width
> > > >>>> + * @r: clip rectangle whose width is returned
> > > >>>> + *
> > > >>>> + * RETURNS:
> > > >>>> + * The width of the clip rectangle.
> > > >>>> + */
> > > >>>> +static inline int drm_clip_rect_width(const struct drm_clip_rect *r)
> > > >>>> +{
> > > >>>> +	return r->x2 - r->x1;
> > > >>>> +}
> > > >>>> +
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_height - determine the clip rectangle height
> > > >>>> + * @r: clip rectangle whose height is returned
> > > >>>> + *
> > > >>>> + * RETURNS:
> > > >>>> + * The height of the clip rectangle.
> > > >>>> + */
> > > >>>> +static inline int drm_clip_rect_height(const struct drm_clip_rect *r)
> > > >>>> +{
> > > >>>> +	return r->y2 - r->y1;
> > > >>>> +}
> > > >>>> +
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_visible - determine if the the clip rectangle is visible
> > > >>>> + * @r: clip rectangle whose visibility is returned
> > > >>>> + *
> > > >>>> + * RETURNS:
> > > >>>> + * %true if the clip rectangle is visible, %false otherwise.
> > > >>>> + */
> > > >>>> +static inline bool drm_clip_rect_visible(const struct drm_clip_rect *r)
> > > >>>> +{
> > > >>>> +	return drm_clip_rect_width(r) > 0 && drm_clip_rect_height(r) > 0;
> > > >>>> +}
> > > >>>> +
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_reset - Reset clip rectangle
> > > >>>> + * @clip: clip rectangle
> > > >>>> + *
> > > >>>> + * Sets clip rectangle to {0,0,0,0}.
> > > >>>> + */
> > > >>>> +static inline void drm_clip_rect_reset(struct drm_clip_rect *clip)
> > > >>>> +{
> > > >>>> +	clip->x1 = 0;
> > > >>>> +	clip->x2 = 0;
> > > >>>> +	clip->y1 = 0;
> > > >>>> +	clip->y2 = 0;
> > > >>>> +}
> > > >>>> +
> > > >>>> +/**
> > > >>>> + * drm_clip_rect_is_empty - Is clip rectangle empty?
> > > >>>> + * @clip: clip rectangle
> > > >>>> + *
> > > >>>> + * Returns true if clip rectangle is {0,0,0,0}.
> > > >>>> + */
> > > >>>> +static inline bool drm_clip_rect_is_empty(struct drm_clip_rect *clip)
> > > >>>> +{
> > > >>>> +	return (!clip->x1 && !clip->x2 && !clip->y1 && !clip->y2);
> > > >>>> +}
> > > >>>> +
> > > >>>> +bool drm_clip_rect_intersect(struct drm_clip_rect *r1,
> > > >>>> +			     const struct drm_clip_rect *r2);
> > > >>>> +void drm_clip_rect_merge(struct drm_clip_rect *dst,
> > > >>>> +			 struct drm_clip_rect *src, unsigned num_clips,
> > > >>>> +			 unsigned flags, u32 width, u32 height);
> > > >>>> +
> > > >>>>    #endif
> > > >>>> -- 
> > > >>>> 2.2.2
> > > >>>>
> > > >>>> _______________________________________________
> > > >>>> dri-devel mailing list
> > > >>>> dri-devel@...ts.freedesktop.org
> > > >>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > 
> > -- 
> > Ville Syrjälä
> > Intel OTC
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@...ts.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Ville Syrjälä
Intel OTC

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