From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kapsi.fi ([217.30.184.167]:58856 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752995Ab2DCKTh (ORCPT ); Tue, 3 Apr 2012 06:19:37 -0400 Message-ID: <4F7ACEB6.9020108@iki.fi> Date: Tue, 03 Apr 2012 13:19:34 +0300 From: Antti Palosaari MIME-Version: 1.0 To: gennarone@gmail.com CC: linux-media@vger.kernel.org, m@bues.ch, hfvogt@gmx.net, mchehab@redhat.com Subject: Re: [PATCH 3/5] tda18218: fix IF frequency for 7MHz bandwidth channels References: <1333401917-27203-1-git-send-email-gennarone@gmail.com> <1333401917-27203-4-git-send-email-gennarone@gmail.com> <4F7A2AC9.8040407@iki.fi> <4F7A47E5.8040604@gmail.com> In-Reply-To: <4F7A47E5.8040604@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 03.04.2012 03:44, Gianluca Gennari wrote: > Il 03/04/2012 00:40, Antti Palosaari ha scritto: >> On 03.04.2012 00:25, Gianluca Gennari wrote: >>> This is necessary to tune VHF channels with the AVerMedia A835 stick. >>> >>> Signed-off-by: Gianluca Gennari >>> --- >>> drivers/media/common/tuners/tda18218.c | 2 +- >>> 1 files changed, 1 insertions(+), 1 deletions(-) >>> >>> diff --git a/drivers/media/common/tuners/tda18218.c >>> b/drivers/media/common/tuners/tda18218.c >>> index dfb3a83..b079696 100644 >>> --- a/drivers/media/common/tuners/tda18218.c >>> +++ b/drivers/media/common/tuners/tda18218.c >>> @@ -144,7 +144,7 @@ static int tda18218_set_params(struct dvb_frontend >>> *fe) >>> priv->if_frequency = 3000000; >>> } else if (bw<= 7000000) { >>> LP_Fc = 1; >>> - priv->if_frequency = 3500000; >>> + priv->if_frequency = 4000000; >>> } else { >>> LP_Fc = 2; >>> priv->if_frequency = 4000000; >> >> Kwaak, I will not apply that until I have done background checking. That >> driver is used only by AF9015 currently. And I did that driver as >> reverse-engineering and thus there is some things guessed. I have only 8 >> MHz wide signal, thus I never tested 7 and 6 MHz. Have no DVB-T >> modulator either... Maybe some AF9015 user can confirm? Is there any >> AF9015& TDA18218 bug reports seen in discussion forums... > > A friend has a AF9015+TDA18218 stick and told me that it works fine with > the patch (including VHF), but to be safe I will ask him to double check > with the current media_build tree, with and without the patch. In the > worst case, we can add a new parameter (or an array of parameters) for > the IF frequency to struct tda18218_config. Public short datasheet [1], page 16, says default IFs are BW=8 MHz IF=4 MHz, BW=7 MHz IF=3.5 MHz, BW=6 MHz IF=3 MHz. I suspect it still locks in some cases even IF is off-by 0.5 MHz for BW 7 and 8 but performance is reduced. So there is now something wrong, likely bug in the tda18218 driver. Could someone send me Windows sniff from success tune to 7 MHz BW channel? [1] http://www.nxp.com/documents/data_sheet/TDA18218HN.pdf -- http://palosaari.fi/