Re: [PATCH 0/5] Driver support for cards based on Digital Devices bridge (ddbridge)

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Em 17-07-2011 04:39, Rémi Denis-Courmont escreveu:
> Le dimanche 17 juillet 2011 03:56:36 Mauro Carvalho Chehab, vous avez écrit :
>>>>> After all, you cannot connect both a DVB-C cable and a DVB-T antenna at
>>>>> the same time, so the vast majority of users won't ever want to switch
>>>>> modes at all.
>>>>
>>>> You are wrong, actually you can. At least here in Finland some cable
>>>> networks offers DVB-T too.
>>
>> As Antti and Rémi pointed, there are issues with some cable operators. Not
>> sure how critical is that, but an userspace application changing it via
>> sysfs might work while the applications are not ported to support both
>> ways.
> 
> Telling applications to use sysfs... I can see many ways that you might regret 
> that in the future...

I'm expressed it badly. What I meant to say is to have some sort of script
or a specific application to allow users to change the delivery system, 
by changing the modprobe parameter, for the MFE drivers supported on <= 3.0 Kernel 
that won't fit in the agreed approach, while applications don't support 
the adopted approach directly.

> Accessing sysfs directly from an application is against all the good practices 
> I thought I had learnt regarding Linux. There is the theoretical possibility 
> that udev gets "explicit" support for Linux DVB and exposes the properties 
> nicely. But that would be rather inconvenient, and cannot be used to change 
> properties.
> 
>> Antti/Rémi, how the current applications work with one physical frontend
>> supporting both DVB-T and DVB-C? Do they allow to change channels from one
>> to the other mode on a transparent way?
> 
> I don't know. VLC does not care if you switch from DVB-T to DVB-C, to the DVD 
> drive or to YouTube. Each channel (or at least each multiplex) is a different 
> playlist item. So it'll close the all device nodes and (re)open them. There 
> are obviously other applications at stake.