From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:1026 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752080Ab0IINMO (ORCPT ); Thu, 9 Sep 2010 09:12:14 -0400 Message-ID: <4C88C25B.70900@redhat.com> Date: Thu, 09 Sep 2010 13:17:47 +0200 From: Hans de Goede MIME-Version: 1.0 To: Peter Korsgaard CC: Hans Verkuil , Jean-Francois Moine , "linux-media@vger.kernel.org" , Andy Walls , eduardo.valentin@nokia.com, ext Eino-Ville Talvala Subject: Re: [PATCH] Illuminators and status LED controls References: <87fwxkcbat.fsf@macbook.be.48ers.dk> <20100909080702.1687d29a@tele> <201009090825.52050.hverkuil@xs4all.nl> <87aanrcsn9.fsf@macbook.be.48ers.dk> In-Reply-To: <87aanrcsn9.fsf@macbook.be.48ers.dk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-ID: Sender: Mauro Carvalho Chehab Hi, On 09/09/2010 08:55 AM, Peter Korsgaard wrote: >>>>>> "Hans" == Hans Verkuil writes: > > Hi, > > >> - the status LED should be controlled by the LED interface. > > Hans> I originally was in favor of controlling these through v4l as > Hans> well, but people made some good arguments against that. The main > Hans> one being: why would you want to show these as a control? What is > Hans> the end user supposed to do with them? It makes little sense. > > Hans> Frankly, why would you want to expose LEDs at all? Shouldn't this > Hans> be completely hidden by the driver? No generic application will > Hans> ever do anything with status LEDs anyway. So it should be the > Hans> driver that operates them and in that case the LEDs do not need > Hans> to be exposed anywhere. > > It's not that it *HAS* to be exposed - But if we can, then it's nice to do > so as it gives flexibility to the user instead of hardcoding policy in > the kernel. > Reading this whole thread I have to agree that if we are going to expose camera status LEDs it would be done through the sysfs API. I think this can be done nicely for gspca based drivers (as we can put all the "crud" in the gspca core having to do it only once), but that is a low priority nice to have thingy. This does leave us with the problem of logitech uvc cams where the LED currently is exposed as a v4l2 control. Regards, Hans