From: Ben Skeggs <bskeggs@redhat.com>
Date: Mon, 18 Jun 2018 18:06:13 +1000
Subject: drm/nouveau/kms/nv50-: cursors always use core channel vram ctxdma
Git-commit: 1264f8325e9b8c004f36f1ae7bacd2a46a7ed771
Patch-mainline: v4.18-rc2
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Ctxdmas for cursors from all heads are setup in the core channel, and due
to us tracking allocated handles per-window, we were failing with -EEXIST
on multiple-head setups trying to allocate duplicate handles.

The cursor code is hardcoded to use the core channel vram ctxdma already,
so just skip ctxdma allocation for cursor fbs to fix the issue.

Fixes: 5bca1621c07 ("drm/nouveau/kms/nv50-: move fb ctxdma tracking into windows")
Reported-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/nouveau/dispnv50/curs507a.c |    2 +-
 drivers/gpu/drm/nouveau/dispnv50/wndw.c     |   13 ++++++++-----
 2 files changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/nouveau/dispnv50/curs507a.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/curs507a.c
@@ -132,7 +132,7 @@ curs507a_new_(const struct nv50_wimm_fun
 
 	nvif_object_map(&wndw->wimm.base.user, NULL, 0);
 	wndw->immd = func;
-	wndw->ctxdma.parent = &disp->core->chan.base.user;
+	wndw->ctxdma.parent = NULL;
 	return 0;
 }
 
--- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
@@ -444,14 +444,17 @@ nv50_wndw_prepare_fb(struct drm_plane *p
 	if (ret)
 		return ret;
 
-	ctxdma = nv50_wndw_ctxdma_new(wndw, fb);
-	if (IS_ERR(ctxdma)) {
-		nouveau_bo_unpin(fb->nvbo);
-		return PTR_ERR(ctxdma);
+	if (wndw->ctxdma.parent) {
+		ctxdma = nv50_wndw_ctxdma_new(wndw, fb);
+		if (IS_ERR(ctxdma)) {
+			nouveau_bo_unpin(fb->nvbo);
+			return PTR_ERR(ctxdma);
+		}
+
+		asyw->image.handle[0] = ctxdma->object.handle;
 	}
 
 	asyw->state.fence = reservation_object_get_excl_rcu(fb->nvbo->bo.resv);
-	asyw->image.handle[0] = ctxdma->object.handle;
 	asyw->image.offset[0] = fb->nvbo->bo.offset;
 
 	if (wndw->func->prepare) {