From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 11 Feb 2015 04:31:14 +0000 (+1030)
Subject: virtio: don't require a config space on the console device.
X-Git-Tag: Ubuntu-snapdragon-4.4.0-1050.54~8687^2~47
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=be8ff5952a8d943660d3c01f1abf4e71eb565fdb;p=mirror_ubuntu-artful-kernel.git

virtio: don't require a config space on the console device.

Strictly, it's only needed when we have features (size or multiport).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 26afb56a8073..fae2dbbf5745 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1986,7 +1986,10 @@ static int virtcons_probe(struct virtio_device *vdev)
 	bool multiport;
 	bool early = early_put_chars != NULL;
 
-	if (!vdev->config->get) {
+	/* We only need a config space if features are offered */
+	if (!vdev->config->get &&
+	    (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
+	     || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
 		dev_err(&vdev->dev, "%s failure: config access disabled\n",
 			__func__);
 		return -EINVAL;