Commit 48c511ed authored Oct 28, 2009 by Devin Heitmueller Committed by Mauro Carvalho Chehab Dec 05, 2009

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>

parent f0cd44b4

drivers/media/common/tuners/mxl5005s.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -2789,7 +2789,10 @@ static u16 MXL_TuneRF(struct dvb_frontend *fe, u32 RF_Freq)

		/* add for 2.6.5 Special setting for QAM */
		if (state->Mod_Type == MXL_QAM) {
		if (state->RF_IN < 680000000)
		if (state->config->qam_gain != 0)
		status += MXL_ControlWrite(fe, RFSYN_CHP_GAIN,
		state->config->qam_gain);
		else if (state->RF_IN < 680000000)
		status += MXL_ControlWrite(fe, RFSYN_CHP_GAIN, 3);
		else
		status += MXL_ControlWrite(fe, RFSYN_CHP_GAIN, 2);

drivers/media/common/tuners/mxl5005s.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -108,6 +108,10 @@ struct mxl5005s_config {
		#define MXL_LOW_IF 1
		u8 if_mode;

		/* Some boards need to override the built-in logic for determining
		the gain when in QAM mode (the HVR-1600 is one such case) */
		u8 qam_gain;

		/* Stuff I don't know what to do with */
		u8 AgcMasterByte;
		};

drivers/media/video/cx18/cx18-dvb.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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,
		};