From: Ezequiel Garcia <ezequiel@collabora.com>
To: linux-media@vger.kernel.org
Cc: kernel@collabora.com, Tomasz Figa <tfiga@chromium.org>,
linux-rockchip@lists.infradead.org,
Heiko Stuebner <heiko@sntech.de>, Jonas Karlman <jonas@kwiboo.se>,
Philipp Zabel <p.zabel@pengutronix.de>,
Boris Brezillon <boris.brezillon@collabora.com>,
Chris Healy <cphealy@gmail.com>,
linux-kernel@vger.kernel.org,
Ezequiel Garcia <ezequiel@collabora.com>
Subject: [PATCH v3 3/3] media: vidioc-enum-fmt.rst: clarify format preference
Date: Wed, 13 Nov 2019 14:56:03 -0300 [thread overview]
Message-ID: <20191113175603.24742-4-ezequiel@collabora.com> (raw)
In-Reply-To: <20191113175603.24742-1-ezequiel@collabora.com>
It has been decided to use the ENUM_FMT index value
as a hint for driver preference. This is defined purposedly
in a very liberal way, letting drivers define what "preference"
means.
For instance, the Hantro VPU driver indicates additional
processing to output a given format, and thus implicates
more CPU usage, which is enumerated after native (non-processed)
formats.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
Documentation/media/uapi/v4l/vidioc-enum-fmt.rst | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
index 399ef1062bac..8ca6ab701e4a 100644
--- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
@@ -44,7 +44,9 @@ To enumerate image formats applications initialize the ``type`` and
the :ref:`VIDIOC_ENUM_FMT` ioctl with a pointer to this structure. Drivers
fill the rest of the structure or return an ``EINVAL`` error code. All
formats are enumerable by beginning at index zero and incrementing by
-one until ``EINVAL`` is returned.
+one until ``EINVAL`` is returned. If applicable, drivers shall return
+formats in preference order, where preferred formats are returned before
+(that is, with lower ``index`` value) less-preferred formats.
.. note::
--
2.22.0
next prev parent reply other threads:[~2019-11-13 17:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-13 17:56 [PATCH v3 0/3] Enable Hantro G1 post-processor Ezequiel Garcia
2019-11-13 17:56 ` [PATCH v3 1/3] media: hantro: Cleanup format negotiation helpers Ezequiel Garcia
2019-11-14 9:26 ` Philipp Zabel
2019-11-14 9:32 ` Boris Brezillon
2019-11-13 17:56 ` [PATCH v3 2/3] media: hantro: Support color conversion via post-processing Ezequiel Garcia
2019-11-13 22:47 ` kbuild test robot
2019-11-14 9:46 ` Boris Brezillon
2019-11-14 9:48 ` Philipp Zabel
2019-11-15 15:44 ` Ezequiel Garcia
2019-11-15 16:10 ` Philipp Zabel
2019-12-05 14:33 ` Ezequiel Garcia
2019-12-05 14:46 ` Philipp Zabel
2019-12-05 16:02 ` Ezequiel Garcia
2019-11-13 17:56 ` Ezequiel Garcia [this message]
2019-11-14 9:32 ` [PATCH v3 3/3] media: vidioc-enum-fmt.rst: clarify format preference Boris Brezillon
2020-02-09 19:52 ` [PATCH v3 0/3] Enable Hantro G1 post-processor Nicolas Dufresne
2020-02-10 2:45 ` Tomasz Figa
2020-02-10 2:45 ` Tomasz Figa
2020-02-11 4:16 ` Nicolas Dufresne
2020-02-11 16:22 ` Nicolas Dufresne
2020-02-12 7:06 ` Tomasz Figa
2020-02-19 21:06 ` Nicolas Dufresne
2020-03-09 11:11 ` Tomasz Figa
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