When the DT node has "wakeup-source", vm_find_vqs() calls
enable_irq_wake() on the shared IRQ, but vm_del_vqs() freed that IRQ
without a matching disable_irq_wake(). That leaves a wake reference
behind and can warn on later free_irq()/request_irq() cycles.

Record whether enable_irq_wake() succeeded, and disable it in
vm_del_vqs() before free_irq().

Fixes: 02213273f72a ("virtio_mmio: add support to set IRQ of a virtio device as wakeup source")
Cc: stable@vger.kernel.org
Signed-off-by: Xiong Weimin <xiongweimin@kylinos.cn>
---
 drivers/virtio/virtio_mmio.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 510b7c4ef..d5b148bde 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -87,6 +87,9 @@ struct virtio_mmio_device {
 
 	void __iomem *base;
 	unsigned long version;
+
+	/* True if enable_irq_wake() succeeded for the shared IRQ. */
+	bool wake_irq_enabled;
 };
 
 /* Configuration interface */
@@ -329,11 +332,17 @@ static void vm_del_vqs(struct virtio_device *vdev)
 {
 	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 	struct virtqueue *vq, *n;
+	int irq = platform_get_irq(vm_dev->pdev, 0);
 
 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 		vm_del_vq(vq);
 
-	free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
+	if (vm_dev->wake_irq_enabled) {
+		disable_irq_wake(irq);
+		vm_dev->wake_irq_enabled = false;
+	}
+
+	free_irq(irq, vm_dev);
 }
 
 static void vm_synchronize_cbs(struct virtio_device *vdev)
@@ -460,8 +469,9 @@ static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
 	if (err)
 		return err;
 
-	if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source"))
-		enable_irq_wake(irq);
+	if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source") &&
+	    !enable_irq_wake(irq))
+		vm_dev->wake_irq_enabled = true;
 
 	for (i = 0; i < nvqs; ++i) {
 		struct virtqueue_info *vqi = &vqs_info[i];
-- 
2.43.0

On the virtio_input thread, Michael asked whether each of these patches
is a real or a theoretical issue for stable. For this virtio_mmio patch:

Real when the DT node has "wakeup-source".

vm_find_vqs() may enable_irq_wake() on the shared IRQ, and vm_del_vqs()
used to free_irq() without disable_irq_wake(), which leaves a wake
reference and can warn on later free/request cycles. Platforms without
that property do not hit it.

Please let me know if you still want Cc: stable on this one.

Thanks,
Xiong

On the virtio_input thread, Michael asked whether each of these patches
is a real or a theoretical issue for stable. For this virtio_mmio patch:

Real when the DT node has "wakeup-source".

vm_find_vqs() may enable_irq_wake() on the shared IRQ, and vm_del_vqs()
used to free_irq() without disable_irq_wake(), which leaves a wake
reference and can warn on later free/request cycles. Platforms without
that property do not hit it.

Please let me know if you still want Cc: stable on this one.

Thanks,
Xiong