Re: [PATCH v2] drm/msm/display: negative x/y in cursor move

[Archit Taneja <architt@codeaurora.org>]

Hi,

On Tuesday 17 July 2018 04:33 AM, Carsten Behling wrote:
> modesetting X11 driver may provide negative x/y cordinates in
> mdp5_crtc_cursor_move call when rotation is enabled.
> 
> Cursor buffer can overlap down to its negative width/height.
> 
> ROI has to be recalculated for negative x/y indicating using the
> lower/right corner of the cursor buffer and hotspot must be set
> in MDP5_LM_CURSOR_XY_SRC_Y MDP5_LM_CURSOR_XY_SRC_X.

Thanks for the patch. Could you tell how to reproduce this issue
on a db410c?

I was playing with xrandr's --rotate and --reflect options to get
a rotated output, but wasn't able to generate negative x/y
co-ordinates. I'm using linaro's debian userspace, running lxqt.

Thanks,
Archit

> 
> Signed-off-by: Carsten Behling <carsten.behling@gmail.com>
> ---
> Changes in v2:
> - fixed format specifier in debug message
> 
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 51 ++++++++++++++++++++++++++-----
>   1 file changed, 43 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
> index 10271359789e..a7f4a6688fec 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
> @@ -65,7 +65,7 @@ struct mdp5_crtc {
>   		struct drm_gem_object *scanout_bo;
>   		uint64_t iova;
>   		uint32_t width, height;
> -		uint32_t x, y;
> +		int x, y;
>   	} cursor;
>   };
>   #define to_mdp5_crtc(x) container_of(x, struct mdp5_crtc, base)
> @@ -760,20 +760,31 @@ static void get_roi(struct drm_crtc *crtc, uint32_t *roi_w, uint32_t *roi_h)
>   	 * Cursor Region Of Interest (ROI) is a plane read from cursor
>   	 * buffer to render. The ROI region is determined by the visibility of
>   	 * the cursor point. In the default Cursor image the cursor point will
> -	 * be at the top left of the cursor image, unless it is specified
> -	 * otherwise using hotspot feature.
> +	 * be at the top left of the cursor image.
>   	 *
> +	 * Without rotation:
>   	 * If the cursor point reaches the right (xres - x < cursor.width) or
>   	 * bottom (yres - y < cursor.height) boundary of the screen, then ROI
>   	 * width and ROI height need to be evaluated to crop the cursor image
>   	 * accordingly.
>   	 * (xres-x) will be new cursor width when x > (xres - cursor.width)
>   	 * (yres-y) will be new cursor height when y > (yres - cursor.height)
> +	 *
> +	 * With rotation:
> +	 * We get negative x and/or y coordinates.
> +	 * (cursor.width - abs(x)) will be new cursor width when x < 0
> +	 * (cursor.height - abs(y)) will be new cursor width when y < 0
>   	 */
> -	*roi_w = min(mdp5_crtc->cursor.width, xres -
> +	if (mdp5_crtc->cursor.x >= 0)
> +		*roi_w = min(mdp5_crtc->cursor.width, xres -
>   			mdp5_crtc->cursor.x);
> -	*roi_h = min(mdp5_crtc->cursor.height, yres -
> +	else
> +		*roi_w = mdp5_crtc->cursor.width - abs(mdp5_crtc->cursor.x);
> +	if (mdp5_crtc->cursor.y >= 0)
> +		*roi_h = min(mdp5_crtc->cursor.height, yres -
>   			mdp5_crtc->cursor.y);
> +	else
> +		*roi_h = mdp5_crtc->cursor.height - abs(mdp5_crtc->cursor.y);
>   }
>   
>   static void mdp5_crtc_restore_cursor(struct drm_crtc *crtc)
> @@ -783,7 +794,7 @@ static void mdp5_crtc_restore_cursor(struct drm_crtc *crtc)
>   	struct mdp5_kms *mdp5_kms = get_kms(crtc);
>   	const enum mdp5_cursor_alpha cur_alpha = CURSOR_ALPHA_PER_PIXEL;
>   	uint32_t blendcfg, stride;
> -	uint32_t x, y, width, height;
> +	uint32_t x, y, src_x, src_y, width, height;
>   	uint32_t roi_w, roi_h;
>   	int lm;
>   
> @@ -800,6 +811,26 @@ static void mdp5_crtc_restore_cursor(struct drm_crtc *crtc)
>   
>   	get_roi(crtc, &roi_w, &roi_h);
>   
> +	/* If cusror buffer overlaps due to rotation on the
> +	 * upper or left screen border the pixel offset inside
> +	 * the cursor buffer of the ROI is the positive overlap
> +	 * distance.
> +	 */
> +	if (mdp5_crtc->cursor.x < 0) {
> +		src_x = abs(mdp5_crtc->cursor.x);
> +		x = 0;
> +	} else {
> +		src_x = 0;
> +	}
> +	if (mdp5_crtc->cursor.y < 0) {
> +		src_y = abs(mdp5_crtc->cursor.y);
> +		y = 0;
> +	} else {
> +		src_y = 0;
> +	}
> +	DBG("%s: x=%u, y=%u roi_w=%u roi_h=%u src_x=%u src_y=%u",
> +		crtc->name, x, y, roi_w, roi_h, src_x, src_y);
> +
>   	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_STRIDE(lm), stride);
>   	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_FORMAT(lm),
>   			MDP5_LM_CURSOR_FORMAT_FORMAT(CURSOR_FMT_ARGB8888));
> @@ -812,6 +843,9 @@ static void mdp5_crtc_restore_cursor(struct drm_crtc *crtc)
>   	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_START_XY(lm),
>   			MDP5_LM_CURSOR_START_XY_Y_START(y) |
>   			MDP5_LM_CURSOR_START_XY_X_START(x));
> +	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_XY(lm),
> +			MDP5_LM_CURSOR_XY_SRC_Y(src_y) |
> +			MDP5_LM_CURSOR_XY_SRC_X(src_x));
>   	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_BASE_ADDR(lm),
>   			mdp5_crtc->cursor.iova);
>   
> @@ -932,8 +966,9 @@ static int mdp5_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
>   	if (unlikely(!crtc->state->enable))
>   		return 0;
>   
> -	mdp5_crtc->cursor.x = x = max(x, 0);
> -	mdp5_crtc->cursor.y = y = max(y, 0);
> +	/* accept negative x/y coordinates up to maximum cursor overlap */
> +	mdp5_crtc->cursor.x = x = max(x, -(int)mdp5_crtc->cursor.width);
> +	mdp5_crtc->cursor.y = y = max(y, -(int)mdp5_crtc->cursor.height);
>   
>   	get_roi(crtc, &roi_w, &roi_h);
>   
>