From ef688e151c00e5d529703be9a04fd506df8bc54e Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Fri, 12 Jun 2009 22:16:35 -0600
Subject: [PATCH] virtio: meet virtio spec by finalizing features before using
device
Virtio devices are supposed to negotiate features before they start using
the device, but the current code doesn't do this. This is because the
driver's probe() function invariably has to add buffers to a virtqueue,
or probe the disk (virtio_blk).
This currently doesn't matter since no existing backend is strict about
the feature negotiation. But it's possible to imagine a future feature
which completely changes how a device operates: in this case, we'd need
to acknowledge it before using the device.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
drivers/virtio/virtio.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 018c070a357f..6b6810364860 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -118,13 +118,14 @@ static int virtio_dev_probe(struct device *_d)
if (device_features & (1 << i))
set_bit(i, dev->features);
+ dev->config->finalize_features(dev);
+
err = drv->probe(dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
- else {
- dev->config->finalize_features(dev);
+ else
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
- }
+
return err;
}
--
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