[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 <k...@umn.edu>
---
 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)