From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v7 2/2] v4l: cadence: Add Cadence MIPI-CSI2 RX driver Date: Thu, 15 Feb 2018 10:50:18 +0100 Message-ID: <20180215095018.hslnarg4ykegqsbo@flea.lan> References: <20180208150830.9219-1-maxime.ripard@bootlin.com> <2517178.9jmyBy62ST@avalon> <20180214131933.t75jg5b5cjfuo7r6@flea.home> <1952975.8AbmfkeE6m@avalon> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="zkbrrwh56qyk3crj" Return-path: Content-Disposition: inline In-Reply-To: <1952975.8AbmfkeE6m@avalon> Sender: linux-media-owner@vger.kernel.org To: Laurent Pinchart Cc: Mauro Carvalho Chehab , Mark Rutland , Rob Herring , linux-media@vger.kernel.org, devicetree@vger.kernel.org, Richard Sproul , Alan Douglas , Steve Creaney , Thomas Petazzoni , Boris Brezillon , Niklas =?iso-8859-1?Q?S=F6derlund?= , Hans Verkuil , Sakari Ailus , Benoit Parrot , nm@ti.com, Simon Hatliff List-Id: devicetree@vger.kernel.org --zkbrrwh56qyk3crj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 14, 2018 at 05:03:26PM +0200, Laurent Pinchart wrote: > On Wednesday, 14 February 2018 15:19:33 EET Maxime Ripard wrote: > > On Thu, Feb 08, 2018 at 08:17:19PM +0200, Laurent Pinchart wrote: > > >> + /* > > >> + * Create a static mapping between the CSI virtual channels > > >> + * and the output stream. > > >> + * > > >> + * This should be enhanced, but v4l2 lacks the support for > > >> + * changing that mapping dynamically. > > >> + * > > >> + * We also cannot enable and disable independant streams here, > > >> + * hence the reference counting. > > >> + */ > > >=20 > > > If you start all streams in one go, will s_stream(1) be called multip= le > > > times ? If not, you could possibly skip the whole reference counting = and > > > avoid locking. > >=20 > > I guess that while we should expect the CSI-2 bus to be always > > enabled, the downstream camera interface could be shutdown > > independently, so I guess s_stream would be called each time one is > > brought up or brought down? >=20 > That's the idea. However, we don't have support for multiplexed streams i= n=20 > mainline yet, so there's no way it can be implemented today in your drive= r. Ok, but we definitely plan on supporting that soon, so I guess that wouldn't too much of a burden to keep it there. Maxime --=20 Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com --zkbrrwh56qyk3crj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE0VqZU19dR2zEVaqr0rTAlCFNr3QFAlqFV9kACgkQ0rTAlCFN r3RU5Q/9H1VTrVPGgvRJJmgI1F8/xIpOdCMFliYvjkxul/fF4fUn5JJiq/PTwApi yzrSKmRrarcYXqNZ1bSwQ9naN7sZHsiRT1L7xKUMPKEeMcWMvCSoCVrO0nrO9aWp OwY4lcTapDwQO1gXmcevgxkMiO+TytcHVUxVYjueeC9fnvqlwpGynmRZuV6/ODZ1 gKOGzqdoAp3s4E4wm9OlrP4AjlgttZ7u4sdfC3bagSeqE0LIwNu4zCapg4toMbWu 8jwBQX84mK3s1270KB3VYBO5kaei/8phAiCNdaOJUD8NuoBqEg/0s9VAJt7DjLuf QXjAbkx9KblNJK6NwYQzkuW1/7baf+eg1gM6SWnFmW0E4QFzxw21Cn5OlJOo/Pm8 uhRox+j+He9ZzmdNNtMja8flZrz7arZfoqiWO+UYKEti8OhrsnrqoIbvE2F+q8Y8 P0BS1WStp4h0tGwmMktK+66oO/ir3sgMkIz+Jt9LO1gbc8/1nUw3jOOwfOnF0GU8 mAQgJX0xJfW3z/aiHIbLgEup/JOoVpiys3b2/uNUPW08sNYIYDTrthHkyZ3dhial MEC17MFx2nMqUf9JMfngLmeZfM6OvPGg/aelmRyslxD7IibWJ1gynozyW7yJnWcZ LBs2cI4+SquekTbyI7HZl3Lz28uhOx8iZR6gsyXQQJxucn7dY7E= =VPeT -----END PGP SIGNATURE----- --zkbrrwh56qyk3crj--