drm/radeon: avoid warnings from r600/eg irq handlers on powered off card.

Since we were calling the wptr function before checking if the IH was
even enabled, or the GPU wasn't shutdown, we'd get spam in the logs when
the GPU readback 0xffffffff. This reorders things so we return early
in the no IH and GPU shutdown cases.

Reported-and-tested-by: ManDay on #radeon
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/evergreen.c

@@ -2695,28 +2695,25 @@ static inline u32 evergreen_get_ih_wptr(struct radeon_device *rdev)
 
 int evergreen_irq_process(struct radeon_device *rdev)
 {
-	u32 wptr = evergreen_get_ih_wptr(rdev);
-	u32 rptr = rdev->ih.rptr;
+	u32 wptr;
+	u32 rptr;
 	u32 src_id, src_data;
 	u32 ring_index;
 	unsigned long flags;
 	bool queue_hotplug = false;
 
-	DRM_DEBUG("r600_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
-	if (!rdev->ih.enabled)
+	if (!rdev->ih.enabled || rdev->shutdown)
 		return IRQ_NONE;
 
-	spin_lock_irqsave(&rdev->ih.lock, flags);
+	wptr = evergreen_get_ih_wptr(rdev);
+	rptr = rdev->ih.rptr;
+	DRM_DEBUG("r600_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
 
+	spin_lock_irqsave(&rdev->ih.lock, flags);
 	if (rptr == wptr) {
 		spin_unlock_irqrestore(&rdev->ih.lock, flags);
 		return IRQ_NONE;
 	}
-	if (rdev->shutdown) {
-		spin_unlock_irqrestore(&rdev->ih.lock, flags);
-		return IRQ_NONE;
-	}
-
 restart_ih:
 	/* display interrupts */
 	evergreen_irq_ack(rdev);

drivers/gpu/drm/radeon/r600.c

@@ -3294,27 +3294,26 @@ static inline u32 r600_get_ih_wptr(struct radeon_device *rdev)
 
 int r600_irq_process(struct radeon_device *rdev)
 {
-	u32 wptr = r600_get_ih_wptr(rdev);
-	u32 rptr = rdev->ih.rptr;
+	u32 wptr;
+	u32 rptr;
 	u32 src_id, src_data;
 	u32 ring_index;
 	unsigned long flags;
 	bool queue_hotplug = false;
 
-	DRM_DEBUG("r600_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
-	if (!rdev->ih.enabled)
+	if (!rdev->ih.enabled || rdev->shutdown)
 		return IRQ_NONE;
 
+	wptr = r600_get_ih_wptr(rdev);
+	rptr = rdev->ih.rptr;
+	DRM_DEBUG("r600_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
+
 	spin_lock_irqsave(&rdev->ih.lock, flags);
 
 	if (rptr == wptr) {
 		spin_unlock_irqrestore(&rdev->ih.lock, flags);
 		return IRQ_NONE;
 	}
-	if (rdev->shutdown) {
-		spin_unlock_irqrestore(&rdev->ih.lock, flags);
-		return IRQ_NONE;
-	}
 
 restart_ih:
 	/* display interrupts */