[Nouveau] [PATCH v2] 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.

v2: do the same in nouveau_pmops_resume

Tested-by: Karl Hastings <kazen at redhat.com>
Signed-off-by: Karol Herbst <kherbst at redhat.com>
---
 drm/nouveau/nouveau_drm.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drm/nouveau/nouveau_drm.c b/drm/nouveau/nouveau_drm.c
index 8d4a5be3..6e4cb4f7 100644
--- a/drm/nouveau/nouveau_drm.c
+++ b/drm/nouveau/nouveau_drm.c
@@ -792,6 +792,27 @@ nouveau_pmops_suspend(struct device *dev)
 	return 0;
 }
 
+static int
+nouveau_set_power_state_D0(struct pci_dev *pdev)
+{
+	struct nouveau_drm *drm = nouveau_drm(pci_get_drvdata(pdev));
+	int ret;
+
+	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)
+		return ret;
+
+	pci_set_master(pdev);
+	return 0;
+}
+
 int
 nouveau_pmops_resume(struct device *dev)
 {
@@ -803,12 +824,9 @@ nouveau_pmops_resume(struct device *dev)
 	    drm_dev->switch_power_state == DRM_SWITCH_POWER_DYNAMIC_OFF)
 		return 0;
 
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
-	ret = pci_enable_device(pdev);
+	ret = nouveau_set_power_state_D0(pdev);
 	if (ret)
 		return ret;
-	pci_set_master(pdev);
 
 	ret = nouveau_do_resume(drm_dev, false);
 
@@ -879,12 +897,9 @@ nouveau_pmops_runtime_resume(struct device *dev)
 		return -EBUSY;
 	}
 
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
-	ret = pci_enable_device(pdev);
+	ret = nouveau_set_power_state_D0(pdev);
 	if (ret)
 		return ret;
-	pci_set_master(pdev);
 
 	ret = nouveau_do_resume(drm_dev, true);
 
-- 
2.14.3