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From: Mauro Carvalho Chehab <mchehab@s-opensource.com>
To: "Honza Petrouš" <jpetrous@gmail.com>
Cc: Linux Doc Mailing List <linux-doc@vger.kernel.org>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
	Mauro Carvalho Chehab <mchehab@infradead.org>,
	linux-kernel@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>
Subject: Re: [PATCH v2 00/26] Improve DVB documentation and reduce its gap
Date: Mon, 4 Sep 2017 08:46:16 -0300	[thread overview]
Message-ID: <20170904084309.7382864a@recife.lan> (raw)
In-Reply-To: <CAJbz7-24qJ8Qz9V_KArhn4uf_3fJwaDcGS399JCZ7nz2O_oBGQ@mail.gmail.com>

Em Mon, 4 Sep 2017 11:40:59 +0200
Honza Petrouš <jpetrous@gmail.com> escreveu:

> > So, IMHO, the interface is broken by design. Perhaps that's
> > the reason why no upstream driver uses it.  
> 
> I have the same feeling regarding brokenness.
> 
> >
> > What seems to be a much better design would be to use the demux
> > set filter ioctls and route the PIDs to the right CA.
> >  
> 
> I don't have access to any programmer reference documentation
> for any modern DVB-enabled SoC, but I see two possible scenario
> of connecting descramblers to the demuxes (most of modern SoCs
> have more then one demux) - static one, when every demux has
> predefined descramblers already connected to it and dynamic ones,
> when any descrambler can be connected to the any demux.

I don't have access to the documentation either, but I know
some designs that have multiple demods that are dynamically set.
Some hardware even allow to dynamically change the maximum amount
of filters per demod at runtime.

> From that reason I vote to have some descrambler specific ioctl,
> which allow more flexibility then if we add it to the filter set ioctl.

I suspect that doing it at the demod does a lot more sense.

Anyway, someone should come with a driver requiring it upstream
for us to discuss and find the better alternatives to support.

Thanks,
Mauro

  reply	other threads:[~2017-09-04 11:46 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-01 13:24 [PATCH v2 00/26] Improve DVB documentation and reduce its gap Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 01/27] media: ca.h: split typedefs from structs Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 02/27] media: dmx.h: " Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 03/27] media: dvb/intro: use the term Digital TV to refer to the system Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 04/27] media: dvb/intro: update references for TV standards Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 05/27] media: dvb/intro: update the history part of the document Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 06/27] media: dvb/intro: adjust the notices about optional hardware Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 07/27] media: dvb/frontend.h: move out a private internal structure Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 08/27] media: dvb/frontend.h: document the uAPI file Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 09/27] media: dvb frontend docs: use kernel-doc documentation Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 10/27] media: fe_property_parameters.rst: better define properties usage Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 11/27] media: fe_property_parameters.rst: better document bandwidth Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 12/27] media: dmx.h: get rid of unused DMX_KERNEL_CLIENT Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 13/27] media: dmx.h: get rid of DMX_GET_CAPS Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 14/27] media: dmx.h: get rid of DMX_SET_SOURCE Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 15/27] media: dmx.h: get rid of GET_DMX_EVENT Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 16/27] media: dmx.h: add kernel-doc markups and use it at Documentation/ Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 17/27] media: net.rst: Fix the level of a section of the net chapter Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 18/27] media: ca.h: get rid of CA_SET_PID Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 19/27] media: ca.h: document most CA data types Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 20/27] media: dst_ca: return a proper error code from CA errors Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 21/27] media: ca-reset.rst: add some description to this ioctl Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 22/27] media: ca-get-cap.rst: document " Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 23/27] media: ca-get-slot-info.rst: " Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 24/27] media: ca-get-descr-info.rst: " Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 25/27] media: dvb CA docs: place undocumented data together with ioctls Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 26/27] media: dvb rst: identify the documentation gap at the API Mauro Carvalho Chehab
2017-09-01 13:24 ` [PATCH v2 27/27] media: dst_ca: remove CA_SET_DESCR boilerplate Mauro Carvalho Chehab
2017-09-03 20:05 ` [PATCH v2 00/26] Improve DVB documentation and reduce its gap Honza Petrouš
2017-09-04  0:54   ` Mauro Carvalho Chehab
2017-09-04  7:12     ` Honza Petrouš
2017-09-04  9:06       ` Mauro Carvalho Chehab
2017-09-04  9:40         ` Honza Petrouš
2017-09-04 11:46           ` Mauro Carvalho Chehab [this message]
2017-09-04  1:17   ` Mauro Carvalho Chehab
2017-09-03 20:31 ` Honza Petrouš

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