drm/vc4: Move IRQ enable to PM path

We were calling enable_irq on bind, where it was already enabled previously
by the IRQ helper. Additionally, dev->irq is not set correctly until after
postinstall and so was always zero here, triggering a warning in 4.15.
Fix both by moving the enable to the power management resume path, where we
know there was a previous disable invocation during suspend.

Fixes: 253696cc ("drm/vc4: Account for interrupts in flight")
Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1514563543-32511-1-git-send-email-stschake@gmail.comTested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/vc4/vc4_irq.c

@@ -209,9 +209,6 @@ vc4_irq_postinstall(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 
-	/* Undo the effects of a previous vc4_irq_uninstall. */
-	enable_irq(dev->irq);
-
 	/* Enable both the render done and out of memory interrupts. */
 	V3D_WRITE(V3D_INTENA, V3D_DRIVER_IRQS);
 

drivers/gpu/drm/vc4/vc4_v3d.c

@@ -327,6 +327,9 @@ static int vc4_v3d_runtime_resume(struct device *dev)
 		return ret;
 
 	vc4_v3d_init_hw(vc4->dev);
+
+	/* We disabled the IRQ as part of vc4_irq_uninstall in suspend. */
+	enable_irq(vc4->dev->irq);
 	vc4_irq_postinstall(vc4->dev);
 
 	return 0;