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-rw-r--r--drivers/virtio/virtio_pci_modern.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 8e5cf194cc0b..4469202eaa8e 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -17,6 +17,7 @@
*
*/
+#include <linux/delay.h>
#define VIRTIO_PCI_NO_LEGACY
#include "virtio_pci_common.h"
@@ -271,9 +272,13 @@ static void vp_reset(struct virtio_device *vdev)
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* 0 status means a reset. */
vp_iowrite8(0, &vp_dev->common->device_status);
- /* Flush out the status write, and flush in device writes,
- * including MSI-X interrupts, if any. */
- vp_ioread8(&vp_dev->common->device_status);
+ /* After writing 0 to device_status, the driver MUST wait for a read of
+ * device_status to return 0 before reinitializing the device.
+ * This will flush out the status write, and flush in device writes,
+ * including MSI-X interrupts, if any.
+ */
+ while (vp_ioread8(&vp_dev->common->device_status))
+ msleep(1);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
}