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)
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).
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.
Regards,
Mauro
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