From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: From: Christophe Thommeret To: linux-dvb@linuxtv.org Date: Thu, 11 Sep 2008 02:01:48 +0200 References: <48B8400A.9030409@linuxtv.org> <20080910161222.21640@gmx.net> <48C85153.8010205@linuxtv.org> In-Reply-To: <48C85153.8010205@linuxtv.org> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200809110201.48935.hftom@free.fr> Subject: Re: [linux-dvb] DVB-S2 / Multiproto and future modulation support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: linux-dvb-bounces@linuxtv.org Errors-To: linux-dvb-bounces+mchehab=infradead.org@linuxtv.org List-ID: Le Thursday 11 September 2008 00:59:31 Andreas Oberritter, vous avez =E9cri= t=A0: > Hans Werner wrote: > >> So applications could know that these 2 frontends are exclusive. > >> That would not require any API change, but would have to be a rule > >> followed by > >> all drivers. > > > > Yes, if we keep to that rule then only frontends which can operate truly > > simultaneously should have a different adapter number. > > An adapter refers to a self-contained piece of hardware, whose parts can > not be used by a second adapter (e.g. adapter0/demux0 can not access the > data from adapter1/frontend1). In a commonly used setup it means that > adapter0 is the first initialized PCI card and adapter1 is the second. > > Now, if you want a device with two tuners that can be accessed > simultaneously to create a second adapter, then you would have to > artificially divide its components so that it looks like two independant > PCI cards. This might become very complicated and limits the functions > of the hardware. > > However, on a setup with multiple accessible tuners you can expect at > least the same amount of accessible demux devices on the same adapter > (and also dvr devices for that matter). There is an ioctl to connect a > frontend to a specific demux (DMX_SET_SOURCE). > > So, if there are demux0, frontend0 and frontend1, then the application > knows that it can't use both frontends simultaneously. Otherwise, if = > there are demux0, demux1, frontend0 and frontend1, then it can use both > of them (by using both demux devices and connecting them to the > frontends via the ioctl mentioned above). Sounds logical. And that's why Kaffeine search for frontend/demux/dvr > 0 a= nd = uses demux1 with frontend1. (That was just a guess since i've never seen = neither any such devices nor comments/recommendations/rules about such case= ). However, all dual tuners devices drivers i know expose the 2 frontends as = frontend0 in separate adapters. But all these devices seems to be USB. The fact that Kaffeine works with the experimental hvr4000 driver indicates = that this driver populates frontend1/demux1/dvr1 and then doesn't follow th= e = way you describe (since the tuners can't be used at once). I would like to hear from Steve on this point. -- = Christophe Thommeret _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb