From 011f0e7a6944855436fb29c7a7e6c3c89c95f8fb 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/console: verify device has config space
Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/console 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/char/virtio_console.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index de03df9dd7c9..26afb56a8073 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1986,6 +1986,12 @@ static int virtcons_probe(struct virtio_device *vdev)
bool multiport;
bool early = early_put_chars != NULL;
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "%s failure: config access disabled\n",
+ __func__);
+ return -EINVAL;
+ }
+
/* Ensure to read early_put_chars now */
barrier();
--
2.34.1