[PATCH] media: lgdt3306a: fix a missing check of return value

[Kangjie Lu]

If lgdt3306a_read_reg() fails, the read data in "val" is incorrect, thus
shouldn't be further used. The fix inserts a check for the return value
of lgdt3306a_read_reg(). If it fails, goto fail.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
---
 drivers/media/dvb-frontends/lgdt3306a.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/dvb-frontends/lgdt3306a.c b/drivers/media/dvb-frontends/lgdt3306a.c
index 0e1f5daaf20c..7410f23314bc 100644
--- a/drivers/media/dvb-frontends/lgdt3306a.c
+++ b/drivers/media/dvb-frontends/lgdt3306a.c
@@ -1685,7 +1685,9 @@ static int lgdt3306a_read_signal_strength(struct dvb_frontend *fe,
 	case QAM_256:
 	case QAM_AUTO:
 		/* need to know actual modulation to set proper SNR baseline */
-		lgdt3306a_read_reg(state, 0x00a6, &val);
+		ret = lgdt3306a_read_reg(state, 0x00a6, &val);
+		if (lg_chkerr(ret))
+			goto fail;
 		if(val & 0x04)
 			ref_snr = 2800; /* QAM-256 28dB */
 		else
-- 
2.17.2 (Apple Git-113)