From: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Date: Wed, 10 Jan 2018 07:20:39 -0500
Subject: media: ts2020: avoid integer overflows on 32 bit machines
Patch-mainline: v4.16-rc1
Git-commit: 81742be14b6a90c9fd0ff6eb4218bdf696ad8e46
References: bsc#1076830
Before this patch, when compiled for arm32, the signal strength
were reported as:
Lock (0x1f) Signal= 4294908.66dBm C/N= 12.79dB
Because of a 32 bit integer overflow. After it, it is properly
reported as:
Lock (0x1f) Signal= -58.64dBm C/N= 12.79dB
Cc: stable@vger.kernel.org
Fixes: 0f91c9d6bab9 ("[media] TS2020: Calculate tuner gain correctly")
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
drivers/media/dvb-frontends/ts2020.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/dvb-frontends/ts2020.c b/drivers/media/dvb-frontends/ts2020.c
index 931e5c98da8a..b879e1571469 100644
--- a/drivers/media/dvb-frontends/ts2020.c
+++ b/drivers/media/dvb-frontends/ts2020.c
@@ -368,7 +368,7 @@ static int ts2020_read_tuner_gain(struct dvb_frontend *fe, unsigned v_agc,
gain2 = clamp_t(long, gain2, 0, 13);
v_agc = clamp_t(long, v_agc, 400, 1100);
- *_gain = -(gain1 * 2330 +
+ *_gain = -((__s64)gain1 * 2330 +
gain2 * 3500 +
v_agc * 24 / 10 * 10 +
10000);
@@ -386,7 +386,7 @@ static int ts2020_read_tuner_gain(struct dvb_frontend *fe, unsigned v_agc,
gain3 = clamp_t(long, gain3, 0, 6);
v_agc = clamp_t(long, v_agc, 600, 1600);
- *_gain = -(gain1 * 2650 +
+ *_gain = -((__s64)gain1 * 2650 +
gain2 * 3380 +
gain3 * 2850 +
v_agc * 176 / 100 * 10 -
--
2.16.2