Nouveau - Nov 2017 - [RFC] drm: don't continue with anything after the GPU couldn't be woken up

This should make systems more stable where resuming the GPU fails. This
can happen due to bad firmware or due to a bug within the kernel. The
last thing which should happen in either case is an unusable system.

Signed-off-by: Karol Herbst <kherbst at redhat.com>
---
 drm/nouveau/nouveau_drm.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drm/nouveau/nouveau_drm.c b/drm/nouveau/nouveau_drm.c
index 8d4a5be3..02892714 100644
--- a/drm/nouveau/nouveau_drm.c
+++ b/drm/nouveau/nouveau_drm.c
@@ -871,7 +871,8 @@ nouveau_pmops_runtime_resume(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct drm_device *drm_dev = pci_get_drvdata(pdev);
-	struct nvif_device *device = &nouveau_drm(drm_dev)->client.device;
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+	struct nvif_device *device = &drm->client.device;
 	int ret;
 
 	if (!nouveau_pmops_runtime()) {
@@ -880,6 +881,11 @@ nouveau_pmops_runtime_resume(struct device *dev)
 	}
 
 	pci_set_power_state(pdev, PCI_D0);
+	/* abort if anything went wrong */
+	if (pdev->current_state != PCI_D0) {
+		NV_ERROR(drm, "couldn't wake up GPU!\n");
+		return -EBUSY;
+	}
 	pci_restore_state(pdev);
 	ret = pci_enable_device(pdev);
 	if (ret)
-- 
2.14.3