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Commit 81742be1 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

media: ts2020: avoid integer overflows on 32 bit machines 



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: 0f91c9d6 ("[media] TS2020: Calculate tuner gain correctly")
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 4852fdca

drivers/media/dvb-frontends/ts2020.c

+2 −2
Original line number Diff line number Diff line
@@ -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 -