From 80bec14b4e0941d1c9eed2830ce364a3ed5694f9 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 17 Jun 2021 13:28:57 +0200 Subject: [PATCH] media: dib8000: rewrite the init prbs logic [ Upstream commit 8db11aebdb8f93f46a8513c22c9bd52fa23263aa ] 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: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/dvb-frontends/dib8000.c | 58 +++++++++++++++++++-------- 1 file changed, 41 insertions(+), 17 deletions(-) diff --git a/drivers/media/dvb-frontends/dib8000.c b/drivers/media/dvb-frontends/dib8000.c index 082796534b0a..bb02354a48b8 100644 --- a/drivers/media/dvb-frontends/dib8000.c +++ b/drivers/media/dvb-frontends/dib8000.c @@ -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;