[PATCH v4 4/5] drm/nouveau/kms: Only allow enabling atomic modesetting on nv50+

[Lyude Paul <lyude@redhat.com>]

Atomic modesetting support was never added for pre-nv50 chipsets, so make
sure we don't allow it to be forced on. Additionally, print a small warning
when it's not supported.

Signed-off-by: Lyude Paul <lyude@redhat.com>

---
V2:
* Check against info.family, not info.chipset

 drivers/gpu/drm/nouveau/nouveau_drm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 9cd12ebc7e449..bfe9d6fe450a5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -769,8 +769,12 @@ nouveau_drm_device_new(struct device *parent, struct nvkm_device *device)
 		goto done;
 	}
 
-	if (nouveau_atomic)
-		drm->drm_driver.driver_features |= DRIVER_ATOMIC;
+	if (nouveau_atomic) {
+		if (drm->device.info.family >= NV_DEVICE_INFO_V0_TESLA)
+			drm->drm_driver.driver_features |= DRIVER_ATOMIC;
+		else
+			NV_WARN(drm, "Atomic modesetting not supported (needs nv50+)\n");
+	}
 
 	ret = nvif_device_map(&drm->device);
 	if (ret) {
-- 
2.55.0