V4L/DVB (13331): mxl5005s: provide ability to override QAM gain for HVR-1600

The HVR-1600 doesn't use the standard mechanism for computing the gain when
in QAM mode, instead always forcing it to be 0x02.  Provide the ability to
override the algorithm on a per-board basis.

This change results in an improvement of 0.4-0.6 dB for QAM tuning.

This work was sponsored by ONELAN Limited.

Cc: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/media/video/cx18/cx18-dvb.c b/drivers/media/video/cx18/cx18-dvb.c
index f402e798e323..54a6fd3f7af5 100644
--- a/drivers/media/video/cx18/cx18-dvb.c
+++ b/drivers/media/video/cx18/cx18-dvb.c
@@ -61,6 +61,7 @@ static struct mxl5005s_config hauppauge_hvr1600_tuner = {
         .top             = MXL5005S_TOP_25P2,
         .mod_mode        = MXL_DIGITAL_MODE,
         .if_mode         = MXL_ZERO_IF,
+        .qam_gain        = 0x02,
         .AgcMasterByte   = 0x00,
 };