From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Sakari Ailus <sakari.ailus@iki.fi>
Cc: linux-media@vger.kernel.org, hverkuil@xs4all.nl,
teturtia@gmail.com, dacohen@gmail.com, snjw23@gmail.com,
andriy.shevchenko@linux.intel.com, t.stanislaws@samsung.com,
tuukkat76@gmail.com, k.debski@gmail.com, riverful@gmail.com
Subject: Re: [PATCH v3 09/33] v4l: Add subdev selections documentation
Date: Fri, 02 Mar 2012 18:54:48 +0100 [thread overview]
Message-ID: <1742252.0cUhcqmAIQ@avalon> (raw)
In-Reply-To: <20120302122439.GC14920@valkosipuli.localdomain>
Hi Sakari,
On Friday 02 March 2012 14:24:40 Sakari Ailus wrote:
> On Tue, Feb 28, 2012 at 12:42:26PM +0100, Laurent Pinchart wrote:
> > On Sunday 26 February 2012 23:42:19 Sakari Ailus wrote:
> > > Laurent Pinchart wrote:
> > > > On Monday 20 February 2012 03:56:48 Sakari Ailus wrote:
> > > >> + </section>
> > > >>
> > > >> - <para>Cropping behaviour on output pads is not defined.</para>
> > > >> + </section>
> > > >> +
> > > >> + <section>
> > > >> + <title>Order of configuration and format propagation</title>
> > > >> +
> > > >> + <para>Inside subdevs, the order of image processing steps will
> > > >> + always be from the sink pad towards the source pad. This is
> > > >> also
> > > >> + reflected in the order in which the configuration must be
> > > >> + performed by the user: the changes made will be propagated to
> > > >> + any subsequent stages. If this behaviour is not desired, the
> > > >> + user must set
> > > >> + <constant>V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG</constant> flag.
> > > >
> > > > Could you explain what happens when V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG
> > > > is
> > > > set ? Just stating that it doesn't follow the propagation behaviour
> > > > previously described could be understood in many different ways.
> > >
> > > Good point. How about this:
> > >
> > > "This flag causes that no propagation of the changes are allowed in any
> > > circumstances. This may also lead the accessed rectangle not being
> > > changed at all,
> >
> > "The accessed rectangle will likely be adjusted by the driver,"
>
> Why "likely"? I think it should say "may" instead, but this of course
> depends on what the user asks.
I'm fine with "The accessed rectangle may be adjusted by the driver" (or
s/may/can/, as adjusting the rectangle is part of the negotiation mechanism
and is thus more likely than not).
> > > depending on the properties of the underlying hardware.
> > > Some drivers may not support this flag."
> >
> > What should happen then ? Should the flag be ignored, or should the driver
> > return an error ?
>
> Only the SMIA++ driver supports this flag so far (as goes for the subdev
> selection interface).
>
> I think it should be ignored. Consider a situation that we add a new flag
> which most of the drivers are unaware of.
>
> As we're adding the flag right at the time the interface is introduced, we
> could also require that all drivers must support it. How about that? In that
> case I'd remove the last sentence of that paragraph.
I think I'd like that better. Otherwise applications would be forced to check
the returned rectangle to find out if the flag was taken into account.
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2012-03-02 17:54 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-20 1:56 [PATCH v3 0/33] V4L2 subdev and sensor control changes, SMIA++ driver and N9 camera board code Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 01/33] v4l: Introduce integer menu controls Sakari Ailus
2012-02-20 17:36 ` Sylwester Nawrocki
2012-02-20 1:56 ` [PATCH v3 02/33] v4l: Document " Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 03/33] vivi: Add an integer menu test control Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 04/33] v4l: VIDIOC_SUBDEV_S_SELECTION and VIDIOC_SUBDEV_G_SELECTION IOCTLs Sakari Ailus
2012-02-21 14:34 ` Laurent Pinchart
2012-02-23 5:49 ` Sakari Ailus
2012-02-21 16:15 ` Laurent Pinchart
2012-02-23 6:01 ` Sakari Ailus
2012-02-27 0:22 ` Laurent Pinchart
2012-02-27 0:57 ` Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 05/33] v4l: vdev_to_v4l2_subdev() should have return type "struct v4l2_subdev *" Sakari Ailus
2012-02-21 14:37 ` Laurent Pinchart
2012-02-20 1:56 ` [PATCH v3 06/33] v4l: Check pad number in get try pointer functions Sakari Ailus
2012-02-21 14:42 ` Laurent Pinchart
2012-02-23 5:57 ` Sakari Ailus
2012-02-27 0:33 ` Laurent Pinchart
2012-02-27 12:27 ` Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 07/33] v4l: Support s_crop and g_crop through s/g_selection Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 08/33] v4l: Add subdev selections documentation: svg and dia files Sakari Ailus
2012-02-21 15:00 ` Laurent Pinchart
2012-02-26 18:56 ` Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 09/33] v4l: Add subdev selections documentation Sakari Ailus
2012-02-21 16:41 ` Laurent Pinchart
2012-02-26 21:42 ` Sakari Ailus
2012-02-28 11:42 ` Laurent Pinchart
2012-03-02 12:24 ` Sakari Ailus
2012-03-02 17:54 ` Laurent Pinchart [this message]
2012-03-02 18:01 ` Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 10/33] v4l: Mark VIDIOC_SUBDEV_G_CROP and VIDIOC_SUBDEV_S_CROP obsolete Sakari Ailus
2012-02-21 16:42 ` Laurent Pinchart
2012-02-20 1:56 ` [PATCH v3 11/33] v4l: Image source control class Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 12/33] v4l: Image processing " Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 13/33] v4l: Document raw bayer 4CC codes Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 14/33] v4l: Add DPCM compressed formats Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 15/33] media: Add link_validate() op to check links to the sink pad Sakari Ailus
2012-02-22 10:05 ` Laurent Pinchart
2012-02-23 15:04 ` Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 16/33] v4l: Improve sub-device documentation for pad ops Sakari Ailus
2012-02-22 10:06 ` Laurent Pinchart
2012-02-20 1:56 ` [PATCH v3 17/33] v4l: Implement v4l2_subdev_link_validate() Sakari Ailus
2012-02-22 10:14 ` Laurent Pinchart
2012-02-23 16:07 ` Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 18/33] v4l: Allow changing control handler lock Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 19/33] omap3isp: Support additional in-memory compressed bayer formats Sakari Ailus
2012-02-20 1:56 ` [PATCH v3 20/33] omap3isp: Move definitions required by board code under include/media Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 21/33] omap3: add definition for CONTROL_CAMERA_PHY_CTRL Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 22/33] omap3isp: Assume media_entity_pipeline_start may fail Sakari Ailus
2012-02-22 10:48 ` Laurent Pinchart
2012-02-26 1:08 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 23/33] omap3isp: Add lane configuration to platform data Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 24/33] omap3isp: Add information on external subdev to struct isp_pipeline Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 25/33] omap3isp: Introduce omap3isp_get_external_info() Sakari Ailus
2012-02-22 10:55 ` Laurent Pinchart
2012-02-26 1:09 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 26/33] omap3isp: Default link validation for ccp2, csi2, preview and resizer Sakari Ailus
2012-02-22 11:01 ` Laurent Pinchart
2012-02-25 1:34 ` Sakari Ailus
2012-02-26 23:14 ` Laurent Pinchart
2012-02-26 23:40 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 27/33] omap3isp: Implement proper CCDC link validation, check pixel rate Sakari Ailus
2012-02-22 11:11 ` Laurent Pinchart
2012-02-25 1:42 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 28/33] omap3isp: Move setting constaints above media_entity_pipeline_start Sakari Ailus
2012-02-22 11:12 ` Laurent Pinchart
2012-02-25 1:46 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 29/33] omap3isp: Configure CSI-2 phy based on platform data Sakari Ailus
2012-02-22 11:21 ` Laurent Pinchart
2012-02-25 1:49 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 30/33] omap3isp: Add resizer data rate configuration to resizer_set_stream Sakari Ailus
2012-02-22 11:24 ` Laurent Pinchart
2012-02-26 1:10 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 31/33] omap3isp: Remove isp_validate_pipeline and other old stuff Sakari Ailus
2012-02-22 11:26 ` Laurent Pinchart
2012-02-25 1:52 ` Sakari Ailus
2012-02-20 1:57 ` [PATCH v3 32/33] smiapp: Add driver Sakari Ailus
2012-02-27 15:38 ` Laurent Pinchart
2012-02-29 5:41 ` Sakari Ailus
2012-02-29 9:35 ` Laurent Pinchart
2012-02-29 10:00 ` Sylwester Nawrocki
2012-03-01 14:01 ` Sakari Ailus
2012-03-01 14:56 ` Laurent Pinchart
2012-02-20 1:57 ` [PATCH v3 33/33] rm680: Add camera init Sakari Ailus
2012-02-27 1:06 ` Laurent Pinchart
2012-02-28 19:05 ` Sakari Ailus
2012-02-20 2:03 ` [PATCH v3 0/33] V4L2 subdev and sensor control changes, SMIA++ driver and N9 camera board code Sakari Ailus
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