From 84c09d723c30db7801433e1741b628e23cb3fecd Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sun, 3 Mar 2013 07:49:50 -0300 Subject: [PATCH] [media] cx231xx: Improve signal reception for PV SBTVD Instead of using 3.3 MHz IF, use 4MHz. That's the standard value for the demod, and, while it can be adjusted, 3.3 MHz is out of the recommended range. So, let's stick with the default. With regards to the IF voltage level, instead of using 0.5 V(p-p) for IF, use 2V, giving a 12dB gain. The rationale is that, on PixelView SBTVD Hybrid, even 2V(p-p) would be in the nominal range for IF, as the maximum range on this particular device is 3V. A higher gain here should help to improve reception under weak signals. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/cx231xx/cx231xx-dvb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/cx231xx/cx231xx-dvb.c b/drivers/media/usb/cx231xx/cx231xx-dvb.c index 7c4e360ba9bc..14e26106fd72 100644 --- a/drivers/media/usb/cx231xx/cx231xx-dvb.c +++ b/drivers/media/usb/cx231xx/cx231xx-dvb.c @@ -89,8 +89,8 @@ static struct tda18271_std_map cnxt_rde253s_tda18271_std_map = { }; static struct tda18271_std_map mb86a20s_tda18271_config = { - .dvbt_6 = { .if_freq = 3300, .agc_mode = 3, .std = 4, - .if_lvl = 7, .rfagc_top = 0x37, }, + .dvbt_6 = { .if_freq = 4000, .agc_mode = 3, .std = 4, + .if_lvl = 0, .rfagc_top = 0x37, }, }; static struct tda18271_config cnxt_rde253s_tunerconfig = { -- 2.11.0