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

[Karol Herbst]

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