From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([213.167.242.64]:34990 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754490AbeGINMY (ORCPT ); Mon, 9 Jul 2018 09:12:24 -0400 From: Laurent Pinchart To: Hans Verkuil Cc: linux-media@vger.kernel.org, Hans Verkuil Subject: Re: [PATCHv5 12/12] media-ioc-enum-entities.rst/-g-topology.rst: clarify ID/name usage Date: Mon, 09 Jul 2018 16:12:57 +0300 Message-ID: <1910449.xYJzjsU7bm@avalon> In-Reply-To: <20180629114331.7617-13-hverkuil@xs4all.nl> References: <20180629114331.7617-1-hverkuil@xs4all.nl> <20180629114331.7617-13-hverkuil@xs4all.nl> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, Thank you for the patch. On Friday, 29 June 2018 14:43:31 EEST Hans Verkuil wrote: > From: Hans Verkuil > > Mention that IDs should not be hardcoded in applications and that the > entity name must be unique within the media topology. > > Signed-off-by: Hans Verkuil > --- > .../uapi/mediactl/media-ioc-enum-entities.rst | 9 +++++--- > .../uapi/mediactl/media-ioc-g-topology.rst | 22 ++++++++++++++----- > 2 files changed, 22 insertions(+), 9 deletions(-) > > diff --git a/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst > b/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst index > 961466ae821d..a4aa7deef690 100644 > --- a/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst > +++ b/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst > @@ -62,15 +62,18 @@ id's until they get an error. > - ``id`` > - > - > - - Entity id, set by the application. When the id is or'ed with > + - Entity id, set by the application. When the ID is or'ed with Should you also s/Entity id/Entity ID/ for consistency ? Apart from that, Reviewed-by: Laurent Pinchart > ``MEDIA_ENT_ID_FLAG_NEXT``, the driver clears the flag and returns > - the first entity with a larger id. > + the first entity with a larger ID. Do not expect that the ID will > + always be the same for each instance of the device. In other words, > + do not hardcode entity IDs in an application. > > * - char > - ``name``\ [32] > - > - > - - Entity name as an UTF-8 NULL-terminated string. > + - Entity name as an UTF-8 NULL-terminated string. This name must be > unique > + within the media topology. > > * - __u32 > - ``type`` > diff --git a/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst > b/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst index > e572dd0d806d..3a5f165d9811 100644 > --- a/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst > +++ b/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst > @@ -131,11 +131,14 @@ desired arrays with the media graph elements. > > * - __u32 > - ``id`` > - - Unique ID for the entity. > + - Unique ID for the entity. Do not expect that the ID will > + always be the same for each instance of the device. In other words, > + do not hardcode entity IDs in an application. > > * - char > - ``name``\ [64] > - - Entity name as an UTF-8 NULL-terminated string. > + - Entity name as an UTF-8 NULL-terminated string. This name must be > unique > + within the media topology. > > * - __u32 > - ``function`` > @@ -166,7 +169,9 @@ desired arrays with the media graph elements. > > * - __u32 > - ``id`` > - - Unique ID for the interface. > + - Unique ID for the interface. Do not expect that the ID will > + always be the same for each instance of the device. In other words, > + do not hardcode interface IDs in an application. > > * - __u32 > - ``intf_type`` > @@ -215,7 +220,9 @@ desired arrays with the media graph elements. > > * - __u32 > - ``id`` > - - Unique ID for the pad. > + - Unique ID for the pad. Do not expect that the ID will > + always be the same for each instance of the device. In other words, > + do not hardcode pad IDs in an application. > > * - __u32 > - ``entity_id`` > @@ -231,7 +238,8 @@ desired arrays with the media graph elements. > returns true. The ``media_version`` is defined in struct > > :c:type:`media_device_info` and can be retrieved using > :ref:`MEDIA_IOC_DEVICE_INFO`. Pad indices are stable. If new pads are > :added > > - for an entity in the future, then those will be added at the end. > + for an entity in the future, then those will be added at the end of the > + entity's pad array. > > * - __u32 > - ``reserved``\ [4] > @@ -250,7 +258,9 @@ desired arrays with the media graph elements. > > * - __u32 > - ``id`` > - - Unique ID for the link. > + - Unique ID for the link. Do not expect that the ID will > + always be the same for each instance of the device. In other words, > + do not hardcode link IDs in an application. > > * - __u32 > - ``source_id`` -- Regards, Laurent Pinchart