[PATCH 1/3] drm: Use original src rect while initializing damage iterator

[Maíra Canal]

Hi Jouni,

On 7/15/22 10:49, Jouni Högander wrote:
> drm_plane_state->src might be modified by the driver. This is done
> e.g. in i915 driver when there is bigger framebuffer than the plane
> and there is some offset within framebuffer. I915 driver calculates
> separate offset and adjusts src rect coords to be relative to this
> offset. Damage clips are still relative to original src coords
> provided by user-space.
> 
> This patch ensures original coordinates provided by user-space are
> used when initiliazing damage iterator.
> 

drm_damage_helper has some KUnit tests on drivers/gpu/drm/tests, and by
applying this patch the drm_damage_helper tests started to fail. Could
you also refactor the drm_damage_helper tests?

To run the tests, you can run:
$ ./tools/testing/kunit/kunit.py run \
--kunitconfig=drivers/gpu/drm/tests \
--kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y \
--kconfig_add CONFIG_VIRTIO_UML=y

There is also some documentation on the DRM KUnit Tests on [1].

[1] https://docs.kernel.org/gpu/drm-internals.html#unit-testing

Best Regards,
- Maíra Canal

> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>> ---
>  drivers/gpu/drm/drm_damage_helper.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
> index 937b699ac2a8..d8b2955e88fd 100644
> --- a/drivers/gpu/drm/drm_damage_helper.c
> +++ b/drivers/gpu/drm/drm_damage_helper.c
> @@ -224,6 +224,7 @@ drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
>  				   const struct drm_plane_state *old_state,
>  				   const struct drm_plane_state *state)
>  {
> +	struct drm_rect src;
>  	memset(iter, 0, sizeof(*iter));
>  
>  	if (!state || !state->crtc || !state->fb || !state->visible)
> @@ -233,10 +234,12 @@ drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
>  	iter->num_clips = drm_plane_get_damage_clips_count(state);
>  
>  	/* Round down for x1/y1 and round up for x2/y2 to catch all pixels */
> -	iter->plane_src.x1 = state->src.x1 >> 16;
> -	iter->plane_src.y1 = state->src.y1 >> 16;
> -	iter->plane_src.x2 = (state->src.x2 >> 16) + !!(state->src.x2 & 0xFFFF);
> -	iter->plane_src.y2 = (state->src.y2 >> 16) + !!(state->src.y2 & 0xFFFF);
> +	src = drm_plane_state_src(state);
> +
> +	iter->plane_src.x1 = src.x1 >> 16;
> +	iter->plane_src.y1 = src.y1 >> 16;
> +	iter->plane_src.x2 = (src.x2 >> 16) + !!(src.x2 & 0xFFFF);
> +	iter->plane_src.y2 = (src.y2 >> 16) + !!(src.y2 & 0xFFFF);
>  
>  	if (!iter->clips || !drm_rect_equals(&state->src, &old_state->src)) {
>  		iter->clips = NULL;