virtio: teach virtio_has_feature() about transport features
Mark McLoughlin [Mon, 11 May 2009 17:11:44 +0000 (18:11 +0100)]
Drivers don't add transport features to their table, so we
shouldn't check these with virtio_check_driver_offered_feature().

We could perhaps add an ->offered_feature() virtio_config_op,
but that perhaps that would be overkill for a consitency check
like this.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

include/linux/virtio_config.h

index 4cd290c..99f5145 100644 (file)
@@ -113,7 +113,9 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
        if (__builtin_constant_p(fbit))
                BUILD_BUG_ON(fbit >= 32);
 
-       virtio_check_driver_offered_feature(vdev, fbit);
+       if (fbit < VIRTIO_TRANSPORT_F_START)
+               virtio_check_driver_offered_feature(vdev, fbit);
+
        return test_bit(fbit, vdev->features);
 }