From: Rusty Russell Date: Wed, 11 Feb 2015 04:31:14 +0000 (+1030) Subject: virtio_pci: use 16-bit accessor for queue_enable. X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7abb568dbb32d055ec6a5633d26fb39fbcd525e3;p=linux-beck.git virtio_pci: use 16-bit accessor for queue_enable. Since PCI is little endian, 8-bit access might work, but the spec section is very clear on this: 4.1.3.1 Driver Requirements: PCI Device Layout The driver MUST access each field using the “natural” access method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit fields and 8-bit accesses for 8-bit fields. Signed-off-by: Rusty Russell Acked-by: Michael S. Tsirkin --- diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index f16e462cb4ef..2aa38e59db2e 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -294,7 +294,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, /* Check if queue is either not available or already active. */ num = ioread16(&cfg->queue_size); - if (!num || ioread8(&cfg->queue_enable)) + if (!num || ioread16(&cfg->queue_enable)) return ERR_PTR(-ENOENT); if (num & (num - 1)) { @@ -394,7 +394,7 @@ static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs, */ list_for_each_entry(vq, &vdev->vqs, list) { iowrite16(vq->index, &vp_dev->common->queue_select); - iowrite8(1, &vp_dev->common->queue_enable); + iowrite16(1, &vp_dev->common->queue_enable); } return 0;