drm/i915: Relax the sprite scaling limits checks

Reduce the size of the the src/dst viewport to keep the scalign ratios
in check.

v2: Below min size sprite handling squashed to previous patch

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 87fe3b625c4b143d3b8a6fead9da15214c812bcf..19b9cb961b5a19ef401434bda5dd1b548ee53deb 100644 (file)
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -681,26 +681,19 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
                        return -EINVAL;
        }
 
+       /*
+        * FIXME the following code does a bunch of fuzzy adjustments to the
+        * coordinates and sizes. We probably need some way to decide whether
+        * more strict checking should be done instead.
+        */
        max_scale = intel_plane->max_downscale << 16;
        min_scale = intel_plane->can_scale ? 1 : (1 << 16);
 
-       hscale = drm_rect_calc_hscale(&src, &dst, min_scale, max_scale);
-       if (hscale < 0) {
-               DRM_DEBUG_KMS("Horizontal scaling factor out of limits\n");
-               drm_rect_debug_print(&src, true);
-               drm_rect_debug_print(&dst, false);
-
-               return hscale;
-       }
-
-       vscale = drm_rect_calc_vscale(&src, &dst, min_scale, max_scale);
-       if (vscale < 0) {
-               DRM_DEBUG_KMS("Vertical scaling factor out of limits\n");
-               drm_rect_debug_print(&src, true);
-               drm_rect_debug_print(&dst, false);
+       hscale = drm_rect_calc_hscale_relaxed(&src, &dst, min_scale, max_scale);
+       BUG_ON(hscale < 0);
 
-               return vscale;
-       }
+       vscale = drm_rect_calc_vscale_relaxed(&src, &dst, min_scale, max_scale);
+       BUG_ON(vscale < 0);
 
        visible = drm_rect_clip_scaled(&src, &dst, &clip, hscale, vscale);
 
@@ -710,6 +703,25 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
        crtc_h = drm_rect_height(&dst);
 
        if (visible) {
+               /* check again in case clipping clamped the results */
+               hscale = drm_rect_calc_hscale(&src, &dst, min_scale, max_scale);
+               if (hscale < 0) {
+                       DRM_DEBUG_KMS("Horizontal scaling factor out of limits\n");
+                       drm_rect_debug_print(&src, true);
+                       drm_rect_debug_print(&dst, false);
+
+                       return hscale;
+               }
+
+               vscale = drm_rect_calc_vscale(&src, &dst, min_scale, max_scale);
+               if (vscale < 0) {
+                       DRM_DEBUG_KMS("Vertical scaling factor out of limits\n");
+                       drm_rect_debug_print(&src, true);
+                       drm_rect_debug_print(&dst, false);
+
+                       return vscale;
+               }
+
                /* Make the source viewport size an exact multiple of the scaling factors. */
                drm_rect_adjust_size(&src,
                                     drm_rect_width(&dst) * hscale - drm_rect_width(&src),
@@ -726,10 +738,6 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
                 * Adjust to (macro)pixel boundary, but be careful not to
                 * increase the source viewport size, because that could
                 * push the downscaling factor out of bounds.
-                *
-                * FIXME Should we be really strict and reject the
-                * config if it results in non (macro)pixel aligned
-                * coords?
                 */
                src_x = src.x1 >> 16;
                src_w = drm_rect_width(&src) >> 16;