[PATCH] drm/amd/display: Fix cursor pos and hotspot calcs

[Michel Dänzer]

On 2018-12-12 3:04 p.m., Nicholas Kazlauskas wrote:
> [Why]
> The cursor calculations in amdgpu_dm incorrectly assume that the
> cursor hotspot is always (0, 0) and don't respect the hot_x and hot_y
> attributes that can be passed in via the drm_mode_cursor2_ioctl.
> 
> The DC hotspot parameters are also incorrectly used to offset the
> cursor when it goes beyond the bounds of the screen instead of
> being clamped.
> 
> [How]
> Use the hot_x and hot_y attributes from the fb to directly fill in the
> DC hotspot attributes.
> 
> Clamp the cursor position on the edges of the screen instead of using
> the hotspot to offset it back in.
> 
> Cc: Leo Li <sunpeng.li at amd.com>
> Cc: Harry Wentland <harry.wentland at amd.com>
> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
> ---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 23 +++++++------------
>  1 file changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 01badda14079..61f2eae0b67f 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -4266,7 +4266,6 @@ static int get_cursor_position(struct drm_plane *plane, struct drm_crtc *crtc,
>  {
>  	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
>  	int x, y;
> -	int xorigin = 0, yorigin = 0;
>  
>  	if (!crtc || !plane->state->fb) {
>  		position->enable = false;
> @@ -4284,24 +4283,18 @@ static int get_cursor_position(struct drm_plane *plane, struct drm_crtc *crtc,
>  		return -EINVAL;
>  	}
>  
> -	x = plane->state->crtc_x;
> -	y = plane->state->crtc_y;
> +	x = plane->state->crtc_x + plane->state->fb->hot_x;
> +	y = plane->state->crtc_y + plane->state->fb->hot_y;
> +
>  	/* avivo cursor are offset into the total surface */
>  	x += crtc->primary->state->src_x >> 16;
>  	y += crtc->primary->state->src_y >> 16;
> -	if (x < 0) {
> -		xorigin = min(-x, amdgpu_crtc->max_cursor_width - 1);
> -		x = 0;
> -	}
> -	if (y < 0) {
> -		yorigin = min(-y, amdgpu_crtc->max_cursor_height - 1);
> -		y = 0;
> -	}
> +
>  	position->enable = true;
> -	position->x = x;
> -	position->y = y;
> -	position->x_hotspot = xorigin;
> -	position->y_hotspot = yorigin;
> +	position->x = x >= 0 ? x : 0;
> +	position->y = y >= 0 ? y : 0;
> +	position->x_hotspot = plane->state->fb->hot_x;
> +	position->y_hotspot = plane->state->fb->hot_y;

I don't see how this could work correctly. Try moving a cursor which
doesn't have the hot spot at the top/left edge (e.g. the X-shaped cursor
used by an X server without any clients) beyond the top/left edge of the
monitor.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer