If we try to scan a sprite outside of the parent CRTC area, the display engine will underflow and potentially blank the framebuffer. So clamp the position + size to the viewable area.
Signed-off-by: Jesse Barnes jbarnes@virtuousgeek.org --- drivers/gpu/drm/i915/intel_overlay2.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_overlay2.c b/drivers/gpu/drm/i915/intel_overlay2.c index 8876857..90c4f59 100644 --- a/drivers/gpu/drm/i915/intel_overlay2.c +++ b/drivers/gpu/drm/i915/intel_overlay2.c @@ -173,6 +173,7 @@ snb_update_plane(struct drm_plane *plane, struct drm_crtc *crtc, u32 reg = DVSCNTR(pipe); int ret = 0; int x = src_x >> 16, y = src_y >> 16; + int active_w = crtc->mode.hdisplay, active_h = crtc->mode.vdisplay;
assert_pipe_enabled(dev_priv, pipe);
@@ -181,6 +182,15 @@ snb_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
old_obj = intel_plane->obj;
+ if (crtc_x >= active_w || crtc_y >= active_h) + return -EINVAL; + + /* Clamp the width & height into the visible area */ + if (crtc_x + crtc_w > active_w) + crtc_w = active_w - crtc_x - 1; + if (crtc_y + crtc_h > active_h) + crtc_h = active_h - crtc_y - 1; + mutex_lock(&dev->struct_mutex);
dvscntr = I915_READ(reg); @@ -242,7 +252,7 @@ snb_update_plane(struct drm_plane *plane, struct drm_crtc *crtc, I915_WRITE(DVSSTRIDE(pipe), fb->pitch); I915_WRITE(DVSPOS(pipe), (crtc_y << 16) | crtc_x); I915_WRITE(DVSTILEOFF(pipe), (y << 16) | x); - I915_WRITE(DVSSIZE(pipe), (fb->height << 16) | fb->width); + I915_WRITE(DVSSIZE(pipe), (crtc_h << 16) | crtc_w); I915_WRITE(DVSSCALE(pipe), 0); I915_WRITE(reg, dvscntr); I915_WRITE(DVSSURF(pipe), start);