[pvrusb2] Problems Tuning Digital Channels on HVR-1950

[Michael Krufky]

On Mon, Nov 24, 2008 at 11:48 AM, roccomoretti <roccomoretti at hotpop.com> wrote:
> Mike Isely wrote:
>> On Thu, 13 Nov 2008, roccomoretti wrote:
>>
>>> The problem is that I can't seem to get the ATSC side of things to work.
>>> I tried following the directions at
>>> http://www.linuxtv.org/wiki/index.php/Testing_your_DVB_device, but
>>> (dvb)scan doesn't find any channels. (It will occasionally find one or
>>> two channels, but I can't get anything consistent.)
>>
>> Which pvrusb2 driver version are you using?  Are you working from a
>> v4l-dvb snapshot?  Which kernel version are you running?
>
> I was using whatever drivers were supplied by Ubuntu 8.10/Intrepid Ibex
> (ones included with the kernel, version "2.6.27-7" - don't ask me what
> that means with respect to the main tree)
>
> Installing a more recent version of v4l-dvb from linuxtv.org using DKMS
> (still with the provided kernel) fixed the problem. (dvb)scan pull out
> most of the local channels, and I'm able to watch digital TV with azap
> and mplayer.

I've been meaning to respond to this all day long, but I've been short
on spare time.  I will keep this short and sweet.

I did a diff comparison between the code in the ubuntu-intrepid kernel
versus the code in the v4l-dvb tree.  The following is a description
of the changes of the major components that have to do with the ATSC /
QAM tuner components in the HVR1950:

1) TDA18271 -- no change (other than some compat code and the removal
of a no-op break statement)

2) S5H1411 -- very small changes.  I looked these over with the author
of the driver and we do not believe these to be causing the issue, but
anything is possible.

3) PVRUSB2 -- some larger changes that I cannot review or describe
fairly given the lack of time that I have for this.

...but this should help Mike and others to troubleshoot the scenario.

I have posted the diff's to the following location:

http://linuxtv.org/~mkrufky/hvr1950

If there is anything questionable about the changes within the pvrusb2
driver, this makes them easy to identify.

Somebody willing to test & work this out should give the s5h1411
changes a try... Again, I doubt they will make any difference, but
anything is possible.

On the bright side, the development repository code is good.  If we
can identify what's wrong with 2.6.27.y, then I can backport the
relevant fix.

I hope this is found useful.

Regards,

Mike Krufky