From 746f7ae0e9ca500f8be888675d88befed5740413 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 25 Apr 2013 11:15:54 -0300 Subject: [PATCH] [media] dib8000: Fix sub-channel range isdbt_sb_subchannel is unsigned with 8 bits. So, it will never be -1. Instead, any value bigger than 13 is invalid. As is, the current code generates the following warnings: drivers/media/dvb-frontends/dib8000.c: In function 'dib8000_set_isdbt_common_channel': drivers/media/dvb-frontends/dib8000.c:2358:3: warning: comparison is always true due to limited range of data type [-Wtype-limits] drivers/media/dvb-frontends/dib8000.c: In function 'dib8000_tune': drivers/media/dvb-frontends/dib8000.c:3107:8: warning: comparison is always false due to limited range of data type [-Wtype-limits] drivers/media/dvb-frontends/dib8000.c:3153:9: warning: comparison is always false due to limited range of data type [-Wtype-limits] drivers/media/dvb-frontends/dib8000.c:3160:5: warning: comparison is always false It should also be noticed that ARIB STD-B31, item "3.15.6.8 Number of segments" at TMCC table defines the value 15 for unused segment, and 14 as reserved. So, better to change the check to consider any value bigger than 13 to mean that sub-channels should be disabled, fixing the warning and doing the right thing even if an invalid value is filled by userspace. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/dib8000.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/media/dvb-frontends/dib8000.c b/drivers/media/dvb-frontends/dib8000.c index 77dac46bfcbf..57863d3fd1cf 100644 --- a/drivers/media/dvb-frontends/dib8000.c +++ b/drivers/media/dvb-frontends/dib8000.c @@ -2355,7 +2355,7 @@ 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 != -1) + if (c->isdbt_sb_subchannel < 14) init_prbs = dib8000_get_init_prbs(state, c->isdbt_sb_subchannel); else init_prbs = 0; @@ -3102,7 +3102,9 @@ static int dib8000_tune(struct dvb_frontend *fe) dib8000_set_isdbt_loop_params(state, LOOP_TUNE_2); /* mpeg will never lock on this condition because init_prbs is not set : search for it !*/ - if (c->isdbt_sb_mode && c->isdbt_sb_subchannel == -1 && !state->differential_constellation) { + if (c->isdbt_sb_mode + && c->isdbt_sb_subchannel < 14 + && !state->differential_constellation) { state->subchannel = 0; *tune_state = CT_DEMOD_STEP_11; } else { @@ -3146,14 +3148,18 @@ static int dib8000_tune(struct dvb_frontend *fe) locks = dib8000_read_lock(fe); if (locks&(1<<(7-state->longest_intlv_layer))) { /* mpeg lock : check the longest one */ dprintk("Mpeg locks [ L0 : %d | L1 : %d | L2 : %d ]", (locks>>7)&0x1, (locks>>6)&0x1, (locks>>5)&0x1); - if (c->isdbt_sb_mode && c->isdbt_sb_subchannel == -1 && !state->differential_constellation) + if (c->isdbt_sb_mode + && c->isdbt_sb_subchannel < 14 + && !state->differential_constellation) /* signal to the upper layer, that there was a channel found and the parameters can be read */ state->status = FE_STATUS_DEMOD_SUCCESS; else state->status = FE_STATUS_DATA_LOCKED; *tune_state = CT_DEMOD_STOP; } else if (now > *timeout) { - if (c->isdbt_sb_mode && c->isdbt_sb_subchannel == -1 && !state->differential_constellation) { /* continue to try init prbs autosearch */ + if (c->isdbt_sb_mode + && c->isdbt_sb_subchannel < 14 + && !state->differential_constellation) { /* continue to try init prbs autosearch */ state->subchannel += 3; *tune_state = CT_DEMOD_STEP_11; } else { /* we are done mpeg of the longest interleaver xas not locking but let's try if an other layer has locked in the same time */