drm/switcheroo: track state of switch in drivers.

We need to track the state of the switch in drivers, so that after s/r
we don't resume the card we've explicitly switched off before. Also
don't allow a userspace open to occur if we've switched the gpu off.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index ec1f650..0568dbd 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1151,12 +1151,16 @@
 	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
 	if (state == VGA_SWITCHEROO_ON) {
 		printk(KERN_INFO "i915: switched on\n");
+		dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
 		/* i915 resume handler doesn't set to D0 */
 		pci_set_power_state(dev->pdev, PCI_D0);
 		i915_resume(dev);
+		dev->switch_power_state = DRM_SWITCH_POWER_ON;
 	} else {
 		printk(KERN_ERR "i915: switched off\n");
+		dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
 		i915_suspend(dev, pmm);
+		dev->switch_power_state = DRM_SWITCH_POWER_OFF;
 	}
 }