[PATCH 1/2] drm/nouveau/fifo/gk104: fix legacy video engine context mappings

[Risto Pajula <or.pajula@gmail.com>]

Commit 8ab849d6dd4c ("drm/nouveau/fifo: add new engine context handling")
made gk104_ectx_ctor() map engine contexts privileged by default.

On GK107, mapping the legacy MSVLD, MSPDEC and MSPPP video engine
contexts privileged causes FIFO PRIV_VIOLATION faults and kills the
channel during VDPAU decoding.

These engines require non-privileged engine context mappings. Keep
privileged mappings for the other engines, but clear the privileged
flag for the legacy video engines.

Fixes: 8ab849d6dd4c ("drm/nouveau/fifo: add new engine context handling")
Assisted-by: LLM
Signed-off-by: Risto Pajula <or.pajula@gmail.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
index 5655eda52..bbeb33cd9 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
@@ -180,6 +180,20 @@ gk104_ectx_ctor(struct nvkm_engn *engn, struct nvkm_vctx *vctx)
 	struct gf100_vmm_map_v0 args = { .priv = 1 };
 	int ret;
 
+	/*
+	 * Legacy video engines access their engine contexts through
+	 * non-privileged MMU requests.
+	 */
+	switch (engn->engine->subdev.type) {
+	case NVKM_ENGINE_MSPDEC:
+	case NVKM_ENGINE_MSPPP:
+	case NVKM_ENGINE_MSVLD:
+		args.priv = 0;
+		break;
+	default:
+		break;
+	}
+
 	ret = nvkm_vmm_get(vctx->vmm, 12, vctx->inst->size, &vctx->vma);
 	if (ret)
 		return ret;
-- 
2.47.3