Em Mon, 16 Apr 2018 15:21:15 +0200
Hans Verkuil <hverk...@xs4all.nl> escreveu:
> From: Hans Verkuil <hansv...@cisco.com>
>
> The __NEED_MEDIA_LEGACY_API define is 1) ugly and 2) dangerous
> since it is all too easy for drivers to define it to get hold of
> legacy defines. Instead just define what we need in media-device.c
> which is the only place where we need the legacy define
> (MEDIA_ENT_T_DEVNODE_UNKNOWN).
>
> Signed-off-by: Hans Verkuil <hansv...@cisco.com>
> ---
> drivers/media/media-device.c | 13 ++++++++++---
> include/uapi/linux/media.h | 2 +-
> 2 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 35e81f7c0d2f..7c3ab37c258a 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -16,9 +16,6 @@
> * GNU General Public License for more details.
> */
>
> -/* We need to access legacy defines from linux/media.h */
> -#define __NEED_MEDIA_LEGACY_API
> -
> #include <linux/compat.h>
> #include <linux/export.h>
> #include <linux/idr.h>
> @@ -35,6 +32,16 @@
>
> #ifdef CONFIG_MEDIA_CONTROLLER
>
> +/*
> + * Legacy defines from linux/media.h. This is the only place we need this
> + * so we just define it here. The media.h header doesn't expose it to the
> + * kernel to prevent it from being used by drivers, but here (and only here!)
> + * we need it to handle the legacy behavior.
> + */
> +#define MEDIA_ENT_SUBTYPE_MASK 0x0000ffff
> +#define MEDIA_ENT_T_DEVNODE_UNKNOWN (MEDIA_ENT_F_OLD_BASE | \
> + MEDIA_ENT_SUBTYPE_MASK)
I don't like much the idea of duplicating defines at C code, but,
in this specific case, I agree that this is better.
Acked-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
> +
> /*
> -----------------------------------------------------------------------------
> * Userspace API
> */
> diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h
> index c7e9a5cba24e..86c7dcc9cba3 100644
> --- a/include/uapi/linux/media.h
> +++ b/include/uapi/linux/media.h
> @@ -348,7 +348,7 @@ struct media_v2_topology {
> #define MEDIA_IOC_SETUP_LINK _IOWR('|', 0x03, struct media_link_desc)
> #define MEDIA_IOC_G_TOPOLOGY _IOWR('|', 0x04, struct media_v2_topology)
>
> -#if !defined(__KERNEL__) || defined(__NEED_MEDIA_LEGACY_API)
> +#ifndef __KERNEL__
>
> /*
> * Legacy symbols used to avoid userspace compilation breakages.
Thanks,
Mauro
