From 8cab3cd6ad622f070b18cd1c2e3b97e1d3806629 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Mon, 12 Jan 2015 16:23:37 +0200
Subject: [PATCH] virtio/scsi: verify device has config space
Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/scsi needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
drivers/scsi/virtio_scsi.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index c52bb5dfaedb..f164f24a4a55 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -950,6 +950,12 @@ static int virtscsi_probe(struct virtio_device *vdev)
u32 num_queues;
struct scsi_host_template *hostt;
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "%s failure: config access disabled\n",
+ __func__);
+ return -EINVAL;
+ }
+
/* We need to know how many queues before we allocate. */
num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
--
2.34.1