From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from ffm.saftware.de ([83.141.3.46]:49495 "EHLO ffm.saftware.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752057Ab1EHJxw (ORCPT ); Sun, 8 May 2011 05:53:52 -0400 Message-ID: <4DC6682C.4060907@linuxtv.org> Date: Sun, 08 May 2011 11:53:48 +0200 From: Andreas Oberritter MIME-Version: 1.0 To: Issa Gorissen CC: Martin Vidovic , Ralph Metzler , linux-media@vger.kernel.org Subject: Re: [PATCH] Ngene cam device name References: <494PeFsCj8960S01.1304706575@web01.cms.usa.net> In-Reply-To: <494PeFsCj8960S01.1304706575@web01.cms.usa.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-ID: Sender: Mauro Carvalho Chehab Hello Issa, On 05/06/2011 08:29 PM, Issa Gorissen wrote: > From: Andreas Oberritter >> On 05/06/2011 03:47 PM, Issa Gorissen wrote: >>> Also, it seems linux en50221 stack provides for the slot selection. So, > why >>> would you need two ca nodes ? >> >> Because it's the most obvious way to use it. And more importantly >> because the API sucks, if you have more than one device per node. You >> can have only one reader, one writer, one poll function per node. For >> example, you can't use one instance of mplayer to watch one channel with >> fe0+dmx0+ca0 and a second instance of mplayer to watch or record another >> channel with fe1+dmx1+ca0. You won't know which device has an event if >> you use poll. The API even allows mixing multiple CI slots and built-in >> descramblers in the same node. But try calling CA_RESET on a specific >> slot or on a descrambler. It won't work. It's broken by design. > > > You need to write a userspace soft which will handle the concurrent access of > your ca device... ... to gain what exactly over using two distinct nodes? How do you propose solving the problem with CA_RESET with a userspace soft? > But for your given example, is there any card allowing you to do that (one ci > slot, two tuners) ? You don't seem to have understood my example. I was explaining some drawbacks of having more than one CI slot, but only one node, answering your prior question. Besides that, it's highly probable that such a card exists. It wouldn't make much sense to hardwire CI slots to tuners, if multiple tuners exist on a board. Disregarding the term "cards", there are variants of the Dreambox with 1, 2 or 4 CI slots combined with 1 to 4 tuners. Regards, Andreas