Re: PCTV 520e on Linux

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

Em 14-10-2011 10:28, Devin Heitmueller escreveu:
> On Fri, Oct 14, 2011 at 9:19 AM, Mauro Carvalho Chehab
> <mchehab@redhat.com> wrote:
>>> While the basic chips used are different, they are completely
>>> different hardware designs and likely have different GPIO
>>> configurations as well as IF specs.
>>
>> The IF settings for xc5000 with DRX-K are solved with this patch:
>>        http://patchwork.linuxtv.org/patch/7932/
>>
>> Basically, DRX-K will use whatever IF the tuner uses.
> 
> While I fundamentally disagree with this change, I'm not going to nack
> it.  That said, this wasn't the issue I was concerned with.  My
> suggestion was simply that you cannot assume that all devices that
> happen to have a particular demod and tuner combo will always use the
> same IF configuration.  The PCB layout can effect the optimal IF.
> 
> This is one of those things that (like many tuners in the LinuxTV
> tree) will probably work good enough to get a signal lock for whoever
> added the board profile, but will result in poor tuning performance
> (and a failure to work in less-than-ideal reception conditions).

This patch doesn't prevent customizing the IF. It will just avoid the
need of setting the IF on both xc5000 and drx-k. Basically, (some) DRX-K
based boards use different IF's depending on the bandwidth and delivery
system type. Instead of adding a complex logic that would allow such
kind of IF adjustments on both, drx-k will simply inquire the tuner about
what IF is currently used.

> 
> All that said, if somebody actually intends to hack on it, I can look
> up what the correct IF is for the 520e.
> 
> Devin
>