On Tue, 9 Feb 2010, Alan Stern wrote: > On Mon, 8 Feb 2010, Guennadi Liakhovetski wrote: > > > To save power soc-camera powers subdevices down, when they are not in use, > > if this is supported by the platform. However, the V4L standard dictates, > > that video nodes shall preserve configuration between uses. This requires > > runtime power management, which is implemented by this patch. It allows > > subdevice drivers to specify their runtime power-management methods, by > > assigning a type to the video device. > > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > > --- > > > > I've posted this patch to linux-media earlier, but I'd also like to get > > comments on linux-pm, sorry to linux-media falks for a duplicate. To > > explain a bit - soc_camera.c is a management module, that binds video > > interfaces on SoCs and sensor drivers. The calls, that I am adding to > > soc_camera.c shall save and restore sensor registers before they are > > powered down and after they are powered up. > > This patch is not correct as it stands. If you use runtime PM then the > system PM resume method has to be changed. See the discussion in > section 6 of Documentation/power/runtime_pm.txt. ...changed - for the same device, right? And I don't see any system PM methods implemented for these devices yet. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
