This is a note to let you know that I've just added the patch titled virtio: virtio 1.0 cs04 spec compliance for reset to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: virtio-virtio-1.0-cs04-spec-compliance-for-reset.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 05dbcb430795b2e1fb1d5c757f8619d3dbed0a1c Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Date: Sun, 3 Apr 2016 15:23:37 +0300 Subject: virtio: virtio 1.0 cs04 spec compliance for reset From: Michael S. Tsirkin <mst@xxxxxxxxxx> commit 05dbcb430795b2e1fb1d5c757f8619d3dbed0a1c upstream. The spec says: after writing 0 to device_status, the driver MUST wait for a read of device_status to return 0 before reinitializing the device. Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/virtio/virtio_pci_modern.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -17,6 +17,7 @@ * */ +#include <linux/delay.h> #define VIRTIO_PCI_NO_LEGACY #include "virtio_pci_common.h" @@ -271,9 +272,13 @@ static void vp_reset(struct virtio_devic struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* 0 status means a reset. */ vp_iowrite8(0, &vp_dev->common->device_status); - /* Flush out the status write, and flush in device writes, - * including MSI-X interrupts, if any. */ - vp_ioread8(&vp_dev->common->device_status); + /* After writing 0 to device_status, the driver MUST wait for a read of + * device_status to return 0 before reinitializing the device. + * This will flush out the status write, and flush in device writes, + * including MSI-X interrupts, if any. + */ + while (vp_ioread8(&vp_dev->common->device_status)) + msleep(1); /* Flush pending VQ/configuration callbacks. */ vp_synchronize_vectors(vdev); } Patches currently in stable-queue which might be from mst@xxxxxxxxxx are queue-4.4/tuntap-restore-default-qdisc.patch queue-4.4/virtio-virtio-1.0-cs04-spec-compliance-for-reset.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html