From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp1-g21.free.fr ([212.27.42.1]:44030 "EHLO smtp1-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753090AbZEWLtS (ORCPT ); Sat, 23 May 2009 07:49:18 -0400 To: Guennadi Liakhovetski Cc: Hans Verkuil , Linux Media Mailing List , Magnus Damm , Darius Augulis , Paul Mundt Subject: Re: [RFC 09/10 v2] v4l2-subdev: re-add s_standby to v4l2_subdev_core_ops References: <200905211533.34827.hverkuil@xs4all.nl> <873aaxxf3d.fsf@free.fr> From: Robert Jarzmik Date: Sat, 23 May 2009 13:49:08 +0200 In-Reply-To: (Guennadi Liakhovetski's message of "Fri\, 22 May 2009 19\:37\:58 +0200 \(CEST\)") Message-ID: <87hbzc6nuz.fsf@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-media-owner@vger.kernel.org List-ID: Guennadi Liakhovetski writes: >> Let me be even more precise about a usecase : >> - a user takes a picture with his smartphone >> - the same user then uses his phone to call his girlfriend >> - the girlfriend has a lot of things to say, it lasts for 1 hour >> In that case, the sensor _has_ to be switched off. > > Nice example, thanks! Ok, of course, we must not leave the poor girl with > her boyfriend's flat battery:-) Dear, of course not, imagine what she would do to him ! :) > I think we can put the camera to a low-power state in streamoff. But - not > power it off! This has to be done from system's PM functions. That means, from a sensor POV, through icd->stop_capture(). For my single mt9m111, it's fine by me, as the mt9m111 does have a powersave mode. Yet I'm wondering if there are sensors without that capability, with only one control (ie. one GPIO line) to switch them on and off ... > What was there on linux-pm about managing power of single devices?... Reference ? Cheers. -- Robert