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. > > >> + */ > > > > > > If you start all streams in one go, will s_stream(1) be called multiple > > > times ? If not, you could possibly skip the whole reference counting and > > > avoid locking. > > > > 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? > > That's the idea. However, we don't have support for multiplexed streams in > mainline yet, so there's no way it can be implemented today in your driver. 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 -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com
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