Den 01.11.2021 15.15, skrev Thomas Zimmermann:
> Enable the FB_DAMAGE_CLIPS property to reduce display-update
> overhead. Also fixes a warning in the kernel log.
>
> simple-framebuffer simple-framebuffer.0: [drm]
> drm_plane_enable_fb_damage_clips() not called
>
> Fix the computation of the blit rectangle. This wasn't an issue so
> far, as simpledrm always blitted the full framebuffer. The code now
> supports damage clipping and virtual screen sizes.
>
> Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
> ---
> drivers/gpu/drm/tiny/simpledrm.c | 30 ++++++++++++++++++++++--------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/tiny/simpledrm.c
> b/drivers/gpu/drm/tiny/simpledrm.c
> index 571f716ff427..e872121e9fb0 100644
> --- a/drivers/gpu/drm/tiny/simpledrm.c
> +++ b/drivers/gpu/drm/tiny/simpledrm.c
> @@ -642,7 +642,7 @@ simpledrm_simple_display_pipe_enable(struct
> drm_simple_display_pipe *pipe,
> void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping
> abstraction */
> struct drm_device *dev = &sdev->dev;
> void __iomem *dst = sdev->screen_base;
> - struct drm_rect clip;
> + struct drm_rect src_clip, dst_clip;
> int idx;
>
> if (!fb)
> @@ -651,10 +651,14 @@ simpledrm_simple_display_pipe_enable(struct
> drm_simple_display_pipe *pipe,
> if (!drm_dev_enter(dev, &idx))
> return;
>
> - drm_rect_init(&clip, 0, 0, fb->width, fb->height);
> + drm_rect_fp_to_int(&src_clip, &plane_state->src);
>
> - dst += drm_fb_clip_offset(sdev->pitch, sdev->format, &clip);
> - drm_fb_blit_toio(dst, sdev->pitch, sdev->format->format, vmap, fb,
> &clip);
> + dst_clip = plane_state->dst;
I assume that src_clip and dst_clip are of the same size, since scaling
is not supported. What prevents dst_clip from being bigger than the
buffer that's being blitted into? Where is that bounds checking done?
Noralf.
> + if (!drm_rect_intersect(&dst_clip, &src_clip))
> + return;
> +
> + dst += drm_fb_clip_offset(sdev->pitch, sdev->format, &dst_clip);
> + drm_fb_blit_toio(dst, sdev->pitch, sdev->format->format, vmap, fb,
> &src_clip);
>
> drm_dev_exit(idx);
> }
> @@ -686,20 +690,28 @@ simpledrm_simple_display_pipe_update(struct
> drm_simple_display_pipe *pipe,
> struct drm_framebuffer *fb = plane_state->fb;
> struct drm_device *dev = &sdev->dev;
> void __iomem *dst = sdev->screen_base;
> - struct drm_rect clip;
> + struct drm_rect damage_clip, src_clip, dst_clip;
> int idx;
>
> if (!fb)
> return;
>
> - if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state,
> &clip))
> + if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state,
> &damage_clip))
> + return;
> +
> + drm_rect_fp_to_int(&src_clip, &plane_state->src);
> + if (!drm_rect_intersect(&src_clip, &damage_clip))
> + return;
> +
> + dst_clip = plane_state->dst;
> + if (!drm_rect_intersect(&dst_clip, &src_clip))
> return;
>
> if (!drm_dev_enter(dev, &idx))
> return;
>
> - dst += drm_fb_clip_offset(sdev->pitch, sdev->format, &clip);
> - drm_fb_blit_toio(dst, sdev->pitch, sdev->format->format, vmap, fb,
> &clip);
> + dst += drm_fb_clip_offset(sdev->pitch, sdev->format, &dst_clip);
> + drm_fb_blit_toio(dst, sdev->pitch, sdev->format->format, vmap, fb,
> &src_clip);
>
> drm_dev_exit(idx);
> }
> @@ -794,6 +806,8 @@ static int simpledrm_device_init_modeset(struct
> simpledrm_device *sdev)
> if (ret)
> return ret;
>
> + drm_plane_enable_fb_damage_clips(&pipe->plane);
> +
> drm_mode_config_reset(dev);
>
> return 0;
>
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