nouveau/gsp: handle engines in runl without nonstall interrupts.

It appears on TU106 GPUs (2070), that some of the nvdec engines
are in the runlist but have no valid nonstall interrupt, nouveau
didn't handle that too well.

This should let nouveau/gsp work on those.

Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://lore.kernel.org/all/20240110011826.3996289-1-airlied@gmail.com/

drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga100.c

@@ -550,6 +550,10 @@ ga100_fifo_nonstall_ctor(struct nvkm_fifo *fifo)
 		struct nvkm_engn *engn = list_first_entry(&runl->engns, typeof(*engn), head);
 
 		runl->nonstall.vector = engn->func->nonstall(engn);
+
+		/* if no nonstall vector just keep going */
+		if (runl->nonstall.vector == -1)
+			continue;
 		if (runl->nonstall.vector < 0) {
 			RUNL_ERROR(runl, "nonstall %d", runl->nonstall.vector);
 			return runl->nonstall.vector;

drivers/gpu/drm/nouveau/nvkm/engine/fifo/r535.c

@@ -350,7 +350,7 @@ r535_engn_nonstall(struct nvkm_engn *engn)
 	int ret;
 
 	ret = nvkm_gsp_intr_nonstall(subdev->device->gsp, subdev->type, subdev->inst);
-	WARN_ON(ret < 0);
+	WARN_ON(ret == -ENOENT);
 	return ret;
 }
 

drivers/gpu/drm/nouveau/nvkm/subdev/gsp/base.c

@@ -25,12 +25,8 @@ int
 nvkm_gsp_intr_nonstall(struct nvkm_gsp *gsp, enum nvkm_subdev_type type, int inst)
 {
 	for (int i = 0; i < gsp->intr_nr; i++) {
-		if (gsp->intr[i].type == type && gsp->intr[i].inst == inst) {
-			if (gsp->intr[i].nonstall != ~0)
-				return gsp->intr[i].nonstall;
-
-			return -EINVAL;
-		}
+		if (gsp->intr[i].type == type && gsp->intr[i].inst == inst)
+			return gsp->intr[i].nonstall;
 	}
 
 	return -ENOENT;