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Commit f538e085 authored by Antti Palosaari's avatar Antti Palosaari Committed by Mauro Carvalho Chehab
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[media] m88ts2022: fix 32bit overflow on filter calc 



Maximum satellite symbol rate used is 45000000Sps which overflows
when multiplied by 135. As final calculation result is fraction,
we could use mult_frac macro in order to keep calculation inside
32 bit number limits and prevent overflow.

Original bug and fix was provided by Nibble Max. I decided to
implement it differently as it is now.

Reported-by: default avatarNibble Max <nibble.max@gmail.com>
Tested-by: default avatarNibble Max <nibble.max@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAntti Palosaari <crope@iki.fi>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent de3f2e2e

drivers/media/tuners/m88ts2022.c

+1 −1
Original line number Diff line number Diff line
@@ -314,7 +314,7 @@ static int m88ts2022_set_params(struct dvb_frontend *fe) 
	div_min = gdiv28 * 78 / 100;

	div_max = clamp_val(div_max, 0U, 63U);



	f_3db_hz = c->symbol_rate * 135UL / 200UL;

	f_3db_hz = mult_frac(c->symbol_rate, 135, 200);

	f_3db_hz +=  2000000U + (frequency_offset_khz * 1000U);

	f_3db_hz = clamp(f_3db_hz, 7000000U, 40000000U);