[PATCH 4.11 056/197] drm/nouveau/kms/nv50: skip core channel cursor update on position-only changes

[Greg Kroah-Hartman]

4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Skeggs <bskeggs@xxxxxxxxxx>

commit e6db95799b1b870aae15682a6d0898df9e9dfb38 upstream.

The DRM core used to only call prepare_fb/cleanup_fb() when a plane's
framebuffer changed, which achieved the desired effect.

It's apparently now up to the driver to decide on its own.

Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/nouveau/nv50_display.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -1113,9 +1113,13 @@ static void
 nv50_curs_prepare(struct nv50_wndw *wndw, struct nv50_head_atom *asyh,
 		  struct nv50_wndw_atom *asyw)
 {
-	asyh->curs.handle = nv50_disp(wndw->plane.dev)->mast.base.vram.handle;
-	asyh->curs.offset = asyw->image.offset;
-	asyh->set.curs = asyh->curs.visible;
+	u32 handle = nv50_disp(wndw->plane.dev)->mast.base.vram.handle;
+	u32 offset = asyw->image.offset;
+	if (asyh->curs.handle != handle || asyh->curs.offset != offset) {
+		asyh->curs.handle = handle;
+		asyh->curs.offset = offset;
+		asyh->set.curs = asyh->curs.visible;
+	}
 }
 
 static void