From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from web38803.mail.mud.yahoo.com ([209.191.125.94]) by www.linuxtv.org with smtp (Exim 4.63) (envelope-from ) id 1Kdf37-00024Y-5l for linux-dvb@linuxtv.org; Thu, 11 Sep 2008 07:49:03 +0200 Date: Wed, 10 Sep 2008 22:48:27 -0700 (PDT) From: Uri Shkolnik To: Christophe Thommeret , Steven Toth In-Reply-To: <48C86DBD.6090108@linuxtv.org> MIME-Version: 1.0 Message-ID: <155463.82037.qm@web38803.mail.mud.yahoo.com> Cc: linux-dvb@linuxtv.org Subject: Re: [linux-dvb] DVB-S2 / Multiproto and future modulation support Reply-To: urishk@yahoo.com 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: --- On Thu, 9/11/08, Steven Toth wrote: > From: Steven Toth > Subject: Re: [linux-dvb] DVB-S2 / Multiproto and future modulation support > To: "Christophe Thommeret" > Cc: linux-dvb@linuxtv.org > Date: Thursday, September 11, 2008, 4:00 AM > Christophe Thommeret wrote: > > Le Thursday 11 September 2008 00:59:31 Andreas > Oberritter, vous avez =E9crit : > >> 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 and = > > 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 the = > > way you describe (since the tuners can't be used > at once). > > I would like to hear from Steve on this point. > > = > > = > = > Correct, frontend1, demux1, dvr1 etc. All on the same > adapter. The = > driver and multi-frontend patches manage exclusive access > to the single = > internal resource. > = > - Steve > = > = > _______________________________________________ > linux-dvb mailing list > linux-dvb@linuxtv.org > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb I wrote about it in a previous post, it's not always so. What about diversi= ty (two frontends, single demux (or non if it's not TS based content)? = _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb