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m88ts2022: fix high symbol rate transponders missing on 32bit platform.

PATCH New nibble.max 1 participant 1 message Aug 16, 2014 Media (V4L/DVB)

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PATCH 1/1 m88ts2022: fix high symbol rate transponders missing on 32bit platform.

The current m88ts2022 driver will miss the following high symbol rate transponders on Telstar 18 138.0. 12385 H 43200,
12690 H 43200,
12538 V 41250...
the code for f_3db_hz will overflow for the high symbol rate.
for example, symbol rate=41250 KS/s
symbol_rate * 135UL = 5568750000(1 4BEC 61B0), the value is larger than unsigned int on 32bit platform. that makes the wrong result.
Exchanging the div and mul position fixs it.

---
 drivers/media/tuners/m88ts2022.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/media/tuners/m88ts2022.c +1 -1
index 40c42de..65c8acc 100644
@@ -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 = (c->symbol_rate / 200UL) * 135UL;
 	f_3db_hz +=  2000000U + (frequency_offset_khz * 1000U);
 	f_3db_hz = clamp(f_3db_hz, 7000000U, 40000000U);
 
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