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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Marek Vasut <marex@denx.de>
Cc: linux-media@vger.kernel.org,
	Alain Volmat <alain.volmat@foss.st.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Amelie DELAUNAY <amelie.delaunay@foss.st.com>,
	Hugues FRUCHET <hugues.fruchet@foss.st.com>,
	Philippe CORNU <philippe.cornu@foss.st.com>,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] media: stm32: dcmi: Register V4L2 subdev nodes
Date: Sun, 19 Jun 2022 03:33:54 +0300	[thread overview]
Message-ID: <Yq5u8sPxZoSVKZ7w@pendragon.ideasonboard.com> (raw)
In-Reply-To: <4dc7b39c-35cd-663a-98f8-6034693df3c8@denx.de>

On Sun, Jun 19, 2022 at 02:28:55AM +0200, Marek Vasut wrote:
> On 6/19/22 01:20, Laurent Pinchart wrote:
> > Hi Marek,
> > 
> > Thank you for the patch.
> > 
> > On Sun, Jun 19, 2022 at 12:23:35AM +0200, Marek Vasut wrote:
> >> Unless the V4L2 device calls v4l2_device_register_subdev_nodes(),
> >> the /dev/v4l-subdev* sub-device nodes are not registered and thus
> >> not created. Add the missing call.
> > 
> > This driver configures the subdevs internally. Exposing the subdev nodes
> > to userspace would conflict with driver operation.
> > 
> > If you need the subdev nodes only to query subdev information, you can
> > use v4l2_device_register_ro_subdev_nodes(). Ideally I'd prefer this
> > driver to expose subdev nodes to userspace and stop propagating formats
> > internally, but that may break applications :-(
> 
> I need those subdevs to configure e.g. test pattern on the sensor side.

Doesn't the dcmi driver expose the sensor controls on the video node ?

-- 
Regards,

Laurent Pinchart

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  reply	other threads:[~2022-06-19  0:36 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-18 22:23 [PATCH] media: stm32: dcmi: Register V4L2 subdev nodes Marek Vasut
2022-06-18 23:20 ` Laurent Pinchart
2022-06-19  0:28   ` Marek Vasut
2022-06-19  0:33     ` Laurent Pinchart [this message]
2022-06-19  0:43       ` Marek Vasut
2022-06-27  8:52         ` Hugues FRUCHET

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