V4L/DVB (6500): tda10021: Fix reported signal strength

Fix reported signal strength value (higher value = higher signal strength).

Signed-off-by: Hartmut Birr <e9hack@googlemail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/media/dvb/frontends/tda10021.c b/drivers/media/dvb/frontends/tda10021.c
index 5ee729846a9f..45137d2ebfb9 100644
--- a/drivers/media/dvb/frontends/tda10021.c
+++ b/drivers/media/dvb/frontends/tda10021.c
@@ -312,7 +312,11 @@ static int tda10021_read_signal_strength(struct dvb_frontend* fe, u16* strength)
 {
         struct tda10021_state* state = fe->demodulator_priv;
 
+        u8 config = tda10021_readreg(state, 0x02);
         u8 gain = tda10021_readreg(state, 0x17);
+        if (config & 0x02)
+                /* the agc value is inverted */
+                gain = ~gain;
         *strength = (gain << 8) | gain;
 
         return 0;