Commit 8db11aeb authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

media: dib8000: rewrite the init prbs logic 



The logic at dib8000_get_init_prbs() has a few issues:

1. the tables used there has an extra unused value at the beginning;
2. the dprintk() message doesn't write the right value when
   transmission mode is not 8K;
3. the array overflow validation is done by the callers.

Rewrite the code to fix such issues.

This should also shut up those smatch warnings:

	drivers/media/dvb-frontends/dib8000.c:2125 dib8000_get_init_prbs() error: buffer overflow 'lut_prbs_8k' 14 <= 14
	drivers/media/dvb-frontends/dib8000.c:2129 dib8000_get_init_prbs() error: buffer overflow 'lut_prbs_2k' 14 <= 14
	drivers/media/dvb-frontends/dib8000.c:2131 dib8000_get_init_prbs() error: buffer overflow 'lut_prbs_4k' 14 <= 14
	drivers/media/dvb-frontends/dib8000.c:2134 dib8000_get_init_prbs() error: buffer overflow 'lut_prbs_8k' 14 <= 14

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 2a621b08

drivers/media/dvb-frontends/dib8000.c

+41 −17
Original line number Diff line number Diff line
@@ -2107,32 +2107,55 @@ static void dib8000_load_ana_fe_coefs(struct dib8000_state *state, const s16 *an 
			dib8000_write_word(state, 117 + mode, ana_fe[mode]);

}



static const u16 lut_prbs_2k[14] = {

	0, 0x423, 0x009, 0x5C7, 0x7A6, 0x3D8, 0x527, 0x7FF, 0x79B, 0x3D6, 0x3A2, 0x53B, 0x2F4, 0x213

static const u16 lut_prbs_2k[13] = {

	0x423, 0x009, 0x5C7,

	0x7A6, 0x3D8, 0x527,

	0x7FF, 0x79B, 0x3D6,

	0x3A2, 0x53B, 0x2F4,

	0x213

};

static const u16 lut_prbs_4k[14] = {

	0, 0x208, 0x0C3, 0x7B9, 0x423, 0x5C7, 0x3D8, 0x7FF, 0x3D6, 0x53B, 0x213, 0x029, 0x0D0, 0x48E



static const u16 lut_prbs_4k[13] = {

	0x208, 0x0C3, 0x7B9,

	0x423, 0x5C7, 0x3D8,

	0x7FF, 0x3D6, 0x53B,

	0x213, 0x029, 0x0D0,

	0x48E

};

static const u16 lut_prbs_8k[14] = {

	0, 0x740, 0x069, 0x7DD, 0x208, 0x7B9, 0x5C7, 0x7FF, 0x53B, 0x029, 0x48E, 0x4C4, 0x367, 0x684



static const u16 lut_prbs_8k[13] = {

	0x740, 0x069, 0x7DD,

	0x208, 0x7B9, 0x5C7,

	0x7FF, 0x53B, 0x029,

	0x48E, 0x4C4, 0x367,

	0x684

};



static u16 dib8000_get_init_prbs(struct dib8000_state *state, u16 subchannel)

{

	int sub_channel_prbs_group = 0;

	int prbs_group;



	sub_channel_prbs_group = (subchannel / 3) + 1;

	dprintk("sub_channel_prbs_group = %d , subchannel =%d prbs = 0x%04x\n", sub_channel_prbs_group, subchannel, lut_prbs_8k[sub_channel_prbs_group]);

	sub_channel_prbs_group = subchannel / 3;

	if (sub_channel_prbs_group >= ARRAY_SIZE(lut_prbs_2k))

		return 0;



	switch (state->fe[0]->dtv_property_cache.transmission_mode) {

	case TRANSMISSION_MODE_2K:

			return lut_prbs_2k[sub_channel_prbs_group];

		prbs_group = lut_prbs_2k[sub_channel_prbs_group];

		break;

	case TRANSMISSION_MODE_4K:

			return lut_prbs_4k[sub_channel_prbs_group];

		prbs_group =  lut_prbs_4k[sub_channel_prbs_group];

		break;

	default:

	case TRANSMISSION_MODE_8K:

			return lut_prbs_8k[sub_channel_prbs_group];

		prbs_group = lut_prbs_8k[sub_channel_prbs_group];

	}



	dprintk("sub_channel_prbs_group = %d , subchannel =%d prbs = 0x%04x\n",

		sub_channel_prbs_group, subchannel, prbs_group);



	return prbs_group;

}



static void dib8000_set_13seg_channel(struct dib8000_state *state)
@@ -2409,10 +2432,8 @@ static void dib8000_set_isdbt_common_channel(struct dib8000_state *state, u8 seq 
	/* TSB or ISDBT ? apply it now */

	if (c->isdbt_sb_mode) {

		dib8000_set_sb_channel(state);

		if (c->isdbt_sb_subchannel < 14)

			init_prbs = dib8000_get_init_prbs(state, c->isdbt_sb_subchannel);

		else

			init_prbs = 0;

		init_prbs = dib8000_get_init_prbs(state,

						  c->isdbt_sb_subchannel);

	} else {

		dib8000_set_13seg_channel(state);

		init_prbs = 0xfff;
@@ -3004,6 +3025,7 @@ static int dib8000_tune(struct dvb_frontend *fe) 


	unsigned long *timeout = &state->timeout;

	unsigned long now = jiffies;

	u16 init_prbs;

#ifdef DIB8000_AGC_FREEZE

	u16 agc1, agc2;

#endif
@@ -3302,8 +3324,10 @@ static int dib8000_tune(struct dvb_frontend *fe) 
		break;



	case CT_DEMOD_STEP_11:  /* 41 : init prbs autosearch */

		if (state->subchannel <= 41) {

			dib8000_set_subchannel_prbs(state, dib8000_get_init_prbs(state, state->subchannel));

		init_prbs = dib8000_get_init_prbs(state, state->subchannel);



		if (init_prbs) {

			dib8000_set_subchannel_prbs(state, init_prbs);

			*tune_state = CT_DEMOD_STEP_9;

		} else {

			*tune_state = CT_DEMOD_STOP;