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path: root/drivers/gpu/drm/drm_rect.c
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Diffstat (limited to 'drivers/gpu/drm/drm_rect.c')
-rw-r--r--drivers/gpu/drm/drm_rect.c74
1 files changed, 58 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
index 9817c1445ba9..8c057829b804 100644
--- a/drivers/gpu/drm/drm_rect.c
+++ b/drivers/gpu/drm/drm_rect.c
@@ -50,13 +50,25 @@ bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
}
EXPORT_SYMBOL(drm_rect_intersect);
+static u32 clip_scaled(u32 src, u32 dst, u32 clip)
+{
+ u64 tmp = mul_u32_u32(src, dst - clip);
+
+ /*
+ * Round toward 1.0 when clipping so that we don't accidentally
+ * change upscaling to downscaling or vice versa.
+ */
+ if (src < (dst << 16))
+ return DIV_ROUND_UP_ULL(tmp, dst);
+ else
+ return DIV_ROUND_DOWN_ULL(tmp, dst);
+}
+
/**
* drm_rect_clip_scaled - perform a scaled clip operation
* @src: source window rectangle
* @dst: destination window rectangle
* @clip: clip rectangle
- * @hscale: horizontal scaling factor
- * @vscale: vertical scaling factor
*
* Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
* same amounts multiplied by @hscale and @vscale.
@@ -66,33 +78,44 @@ EXPORT_SYMBOL(drm_rect_intersect);
* %false otherwise
*/
bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
- const struct drm_rect *clip,
- int hscale, int vscale)
+ const struct drm_rect *clip)
{
int diff;
diff = clip->x1 - dst->x1;
if (diff > 0) {
- int64_t tmp = src->x1 + (int64_t) diff * hscale;
- src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+ u32 new_src_w = clip_scaled(drm_rect_width(src),
+ drm_rect_width(dst), diff);
+
+ src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX);
+ dst->x1 = clip->x1;
}
diff = clip->y1 - dst->y1;
if (diff > 0) {
- int64_t tmp = src->y1 + (int64_t) diff * vscale;
- src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+ u32 new_src_h = clip_scaled(drm_rect_height(src),
+ drm_rect_height(dst), diff);
+
+ src->y1 = clamp_t(int64_t, src->y2 - new_src_h, INT_MIN, INT_MAX);
+ dst->y1 = clip->y1;
}
diff = dst->x2 - clip->x2;
if (diff > 0) {
- int64_t tmp = src->x2 - (int64_t) diff * hscale;
- src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+ u32 new_src_w = clip_scaled(drm_rect_width(src),
+ drm_rect_width(dst), diff);
+
+ src->x2 = clamp_t(int64_t, src->x1 + new_src_w, INT_MIN, INT_MAX);
+ dst->x2 = clip->x2;
}
diff = dst->y2 - clip->y2;
if (diff > 0) {
- int64_t tmp = src->y2 - (int64_t) diff * vscale;
- src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+ u32 new_src_h = clip_scaled(drm_rect_height(src),
+ drm_rect_height(dst), diff);
+
+ src->y2 = clamp_t(int64_t, src->y1 + new_src_h, INT_MIN, INT_MAX);
+ dst->y2 = clip->y2;
}
- return drm_rect_intersect(dst, clip);
+ return drm_rect_visible(dst);
}
EXPORT_SYMBOL(drm_rect_clip_scaled);
@@ -106,7 +129,10 @@ static int drm_calc_scale(int src, int dst)
if (dst == 0)
return 0;
- scale = src / dst;
+ if (src > (dst << 16))
+ return DIV_ROUND_UP(src, dst);
+ else
+ scale = src / dst;
return scale;
}
@@ -121,6 +147,10 @@ static int drm_calc_scale(int src, int dst)
* Calculate the horizontal scaling factor as
* (@src width) / (@dst width).
*
+ * If the scale is below 1 << 16, round down. If the scale is above
+ * 1 << 16, round up. This will calculate the scale with the most
+ * pessimistic limit calculation.
+ *
* RETURNS:
* The horizontal scaling factor, or errno of out of limits.
*/
@@ -152,6 +182,10 @@ EXPORT_SYMBOL(drm_rect_calc_hscale);
* Calculate the vertical scaling factor as
* (@src height) / (@dst height).
*
+ * If the scale is below 1 << 16, round down. If the scale is above
+ * 1 << 16, round up. This will calculate the scale with the most
+ * pessimistic limit calculation.
+ *
* RETURNS:
* The vertical scaling factor, or errno of out of limits.
*/
@@ -189,6 +223,10 @@ EXPORT_SYMBOL(drm_rect_calc_vscale);
* If the calculated scaling factor is above @max_vscale,
* decrease the height of rectangle @src to compensate.
*
+ * If the scale is below 1 << 16, round down. If the scale is above
+ * 1 << 16, round up. This will calculate the scale with the most
+ * pessimistic limit calculation.
+ *
* RETURNS:
* The horizontal scaling factor.
*/
@@ -239,6 +277,10 @@ EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);
* If the calculated scaling factor is above @max_vscale,
* decrease the height of rectangle @src to compensate.
*
+ * If the scale is below 1 << 16, round down. If the scale is above
+ * 1 << 16, round up. This will calculate the scale with the most
+ * pessimistic limit calculation.
+ *
* RETURNS:
* The vertical scaling factor.
*/
@@ -373,8 +415,8 @@ EXPORT_SYMBOL(drm_rect_rotate);
* them when doing a rotatation and its inverse.
* That is, if you do ::
*
- * DRM_MODE_PROP_ROTATE(&r, width, height, rotation);
- * DRM_MODE_ROTATE_inv(&r, width, height, rotation);
+ * drm_rect_rotate(&r, width, height, rotation);
+ * drm_rect_rotate_inv(&r, width, height, rotation);
*
* you will always get back the original rectangle.
*/