Re: Problems tuning PAL-D with a Hauppauge HVR-1110 (TDA18271 tuner) - workaround hack included

From: Mauro Carvalho Chehab <mchehab@infradead.org>
To: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Cc: LMML <linux-media@vger.kernel.org>,
	Michael Krufky <mkrufky@kernellabs.com>,
	devin heitmueller <dheitmueller@kernellabs.com>
Subject: Re: Problems tuning PAL-D with a Hauppauge HVR-1110 (TDA18271 tuner) - workaround hack included
Date: Fri, 30 Sep 2011 10:35:34 -0300	[thread overview]
Message-ID: <4E85C5A6.2030805@infradead.org> (raw)
In-Reply-To: <201109301211.41984.simon.farnsworth@onelan.co.uk>

Em 30-09-2011 08:11, Simon Farnsworth escreveu:
> On Friday 30 September 2011, Mauro Carvalho Chehab <mchehab@infradead.org> wrote:
>> Em 28-09-2011 09:50, Simon Farnsworth escreveu:
>>> (note - the CC list is everyone over 50% certainty from get_maintainer.pl)
>>>
>>> I'm having problems getting a Hauppauge HVR-1110 card to successfully
>>> tune PAL-D at 85.250 MHz vision frequency; by experimentation, I've
>>> determined that the tda18271 is tuning to a frequency 1.25 MHz lower
>>> than the vision frequency I've requested, so the following workaround
>>> "fixes" it for me.
>>>
>>> diff --git a/drivers/media/common/tuners/tda18271-fe.c 
>>> b/drivers/media/common/tuners/tda18271-fe.c
>>> index 63cc400..1a94e1a 100644
>>> --- a/drivers/media/common/tuners/tda18271-fe.c
>>> +++ b/drivers/media/common/tuners/tda18271-fe.c
>>> @@ -1031,6 +1031,7 @@ static int tda18271_set_analog_params(struct 
>>> dvb_frontend *fe,
>>>  		mode = "I";
>>>  	} else if (params->std & V4L2_STD_DK) {
>>>  		map = &std_map->atv_dk;
>>> +                freq += 1250000;
>>>  		mode = "DK";
>>>  	} else if (params->std & V4L2_STD_SECAM_L) {
>>>  		map = &std_map->atv_l;
>>
>> If I am to fix this bug, instead of a hack like that, it seems to be better
>> to split the .atv_dk line at the struct tda18271_std_map maps on
>> drivers/media/common/tuners/tda18271-maps.c.
>>
>> Looking at the datasheet, on page 43, available at:
>> 	http://www.nxp.com/documents/data_sheet/TDA18271HD.pdf
>>
>> The offset values for IF seem ok, but maybe your device is using some variant
>> of this chip that requires a different maps table.
>>
> How would I identify that?
> 
> I definitely need the hack on multiple different HVR1110 cards, in different
> motherboards, so if it's a new variant needing a new maps table, it should
> be possible to distinguish it from the other devices somehow - but I have no
> idea how.

The tveeprom.c uses the board eeprom to read the tuner model. I might be wrong, but
when Hauppauge uses a different component, a new entry is created there.

Regards,
Mauro