Now that all V4L2 drivers set device_caps in struct video_device, we can add a check for this to ensure all future drivers fill this in. Also verify that when the querycap ioctl is called the driver didn't mess with the device_caps value and that capabilities is a superset of device_caps. Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> --- diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index cbb74f748555..3af72e3bbd65 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c @@ -859,6 +859,9 @@ int __video_register_device(struct video_device *vdev, /* the v4l2_dev pointer MUST be present */ if (WARN_ON(!vdev->v4l2_dev)) return -EINVAL; + /* the device_caps field MUST be set */ + if (WARN_ON(!vdev->device_caps)) + return -EINVAL; /* v4l2_fh support */ spin_lock_init(&vdev->fh_lock); diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index e36629ae2203..61846c355627 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -1057,14 +1057,18 @@ static int v4l_querycap(const struct v4l2_ioctl_ops *ops, ret = ops->vidioc_querycap(file, fh, cap); - cap->capabilities |= V4L2_CAP_EXT_PIX_FORMAT; /* - * Drivers MUST fill in device_caps, so check for this and - * warn if it was forgotten. + * Drivers must not change device_caps, so check for this and + * warn if this happened. + */ + WARN_ON(cap->device_caps != vfd->device_caps); + /* + * Check that capabilities is a superset of + * vfd->device_caps | V4L2_CAP_DEVICE_CAPS */ - WARN(!(cap->capabilities & V4L2_CAP_DEVICE_CAPS) || - !cap->device_caps, "Bad caps for driver %s, %x %x", - cap->driver, cap->capabilities, cap->device_caps); + WARN_ON((cap->capabilities & (vfd->device_caps | V4L2_CAP_DEVICE_CAPS)) != + (vfd->device_caps | V4L2_CAP_DEVICE_CAPS)); + cap->capabilities |= V4L2_CAP_EXT_PIX_FORMAT; cap->device_caps |= V4L2_CAP_EXT_PIX_FORMAT; return ret;
