Comment 5 for bug 1249978

Checking drivers/acpi/video.c also found it outputs a warning message but with no control flow changes as below:

static int acpi_video_bus_check(struct acpi_video_bus *video)
{
        ...
        /* Does this device support video switching? */
        if (video->cap._DOS || video->cap._DOD) {
                if (!video->cap._DOS) {
                        printk(KERN_WARNING FW_BUG
                                "ACPI(%s) defines _DOD but not _DOS\n",
                                acpi_device_bid(video->device));
                }
                video->flags.multihead = 1;
                status = 0;
        }
}

Therefore it is safe to ignore it. We will also investigate whether it is appropriate to lower the severity in fwts.

        ...