drm/i915: properly check for pipe count

As suggested by Chris Wilson and Daniel Vetter, this chunk of code can be
simplified with a more simple check.

Also, as noticed by Jesse Barnes, it is worth mentioning that plane is an
enum and num_pipe is an int, so we could be more paranoid here about those
validation checks eventually.

CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 4 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 45b93a096191..6b93d4a697ed 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1980,16 +1980,10 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
                 return 0;
         }
 
-        switch (intel_crtc->plane) {
-        case 0:
-        case 1:
-                break;
-        case 2:
-                if (IS_IVYBRIDGE(dev))
-                        break;
-                /* fall through otherwise */
-        default:
-                DRM_ERROR("no plane for crtc\n");
+        if(intel_crtc->plane > dev_priv->num_pipe) {
+                DRM_ERROR("no plane for crtc: plane %d, num_pipes %d\n",
+                                intel_crtc->plane,
+                                dev_priv->num_pipe);
                 return -EINVAL;
         }