From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lb0-f174.google.com ([209.85.217.174]:51855 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754287Ab2IWRyJ (ORCPT ); Sun, 23 Sep 2012 13:54:09 -0400 Received: by lbbgj3 with SMTP id gj3so5804365lbb.19 for ; Sun, 23 Sep 2012 10:54:07 -0700 (PDT) Message-ID: <505F4CBC.1000201@gmail.com> Date: Sun, 23 Sep 2012 19:54:04 +0200 From: Anders Thomson MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: "linux-media@vger.kernel.org" Subject: Re: tda8290 regression fix References: <503F4E19.1050700@gmail.com> <20120915133417.27cb82a1@redhat.com> <5054BD53.7060109@gmail.com> <20120915145834.0b763f73@redhat.com> <5054C521.1090200@gmail.com> <20120915192530.74aedaa6@redhat.com> <50559241.6070408@gmail.com> <505844A0.30001@redhat.com> <5059C242.3010902@gmail.com> <5059F68F.4050009@redhat.com> <505A1C16.40507@gmail.com> <505C7E64.4040507@redhat.com> <8ed8c988-fa8c-41fc-9f33-cccdceb1b232@email.android.com> <505EF455.9080604@redhat.com> In-Reply-To: <505EF455.9080604@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 2012-09-23 13:36, Mauro Carvalho Chehab wrote: > Em 22-09-2012 11:32, Anders Eriksson escreveu: > > Not to my knowledge. It's a standard antenna cable to my cabletv box. I watch tv over hdmi to get HD. I only use analogue (and this htpc card) to record stuff. > > (please, don't top-post - it makes harder to preserve the history of the > discussions) Sorry about that. I was using my notsosmartphone. > > Then, maybe that's the reason why you're having troubles with this board. > > The tda8290-based devices have two components: > > 1) a tda8275 tuner, at address 0x61 at the 7-bit I2C address notation > (or 0xc2, at the 8-bit notation); > 2) a tda8290 analog demod at address 0x4b (7-bit notation). > > Some devices provide a way to send power to a low noise amplifier located at the > antenna or at the device itself (called LNA). The way to activate the LNA is > board-dependent. > > On some devices the tda8290 can also be used to enable/disable a linear amplifier > (LNA). Enabling/disabling the LNA and its gain affects the quality of the signal. > > In the case of tda8275/tda8290 based devices, the LNA setup type is stored at > priv->cfg->config, where: > > 0 - means no LNA control at all - device won't use it; > 1, 2 - LNA is via a pin at tda8290 (GPIO 0): > When config is 1, LNA high gain happens writing a 0; > When config is 2, LNA high gain happens writing a 1; > 3 - The LNA gain control is via a pin at saa713x. > > For modes 1 and 2, the switch_addr should be equal to 0x4b, as the commands > sent to the device are for the tda8290 chip; sending them to tda8275 will > likely produce no results or would affect something else there. > > I suspect that, in the case of your board, the LNA is at the antenna bundled > together with the device. If I'm right, by enabling LNA, your board is sending > some voltage through the cabling (you could easily check it with a voltmeter). I actually have a multimeter somewhere. We're talking about the antenna-in (unconnected) on the card, right? And what voltages should I expect? > > What I think that your patch is actually doing is to disable LNA. As such, it > should be equivalent to: > > > diff --git a/drivers/media/pci/saa7134/saa7134-cards.c b/drivers/media/pci/saa7134/saa7134-cards.c > index bc08f1d..98b482e 100644 > --- a/drivers/media/pci/saa7134/saa7134-cards.c > +++ b/drivers/media/pci/saa7134/saa7134-cards.c > @@ -3288,13 +3288,13 @@ struct saa7134_board saa7134_boards[] = { > .name = "Pinnacle PCTV 310i", > .audio_clock = 0x00187de7, > .tuner_type = TUNER_PHILIPS_TDA8290, > .radio_type = UNSET, > .tuner_addr = ADDR_UNSET, > .radio_addr = ADDR_UNSET, > - .tuner_config = 1, > + .tuner_config = 0, > .mpeg = SAA7134_MPEG_DVB, > .gpiomask = 0x000200000, > .inputs = {{ > .name = name_tv, > .vmux = 4, > .amux = TV, > > > Please test if the above patch fixes the issue you're suffering[1]. If so, then > we'll need to add a modprobe parameter to allow disabling LNA for saa7134 devices > with LNA. > > [1] Note: the above is not the fix, as some users of this board may be using the > original antenna, and changing tuner_config will break things for them; the right > fix is likely to allow controlling the LNA via userspace. Tried that patch on 3.5.3. No improvement, unfortunately. Regards, /Anders