| From f538e085138e519e25ae0828bd6c6e7492ce8ca4 Mon Sep 17 00:00:00 2001 |
| From: Antti Palosaari <crope@iki.fi> |
| Date: Thu, 21 Aug 2014 14:02:27 -0300 |
| Subject: media: m88ts2022: fix 32bit overflow on filter calc |
| |
| From: Antti Palosaari <crope@iki.fi> |
| |
| commit f538e085138e519e25ae0828bd6c6e7492ce8ca4 upstream. |
| |
| 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: Nibble Max <nibble.max@gmail.com> |
| Tested-by: Nibble Max <nibble.max@gmail.com> |
| Signed-off-by: Antti Palosaari <crope@iki.fi> |
| Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/media/tuners/m88ts2022.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/media/tuners/m88ts2022.c |
| +++ b/drivers/media/tuners/m88ts2022.c |
| @@ -314,7 +314,7 @@ static int m88ts2022_set_params(struct d |
| 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); |
| |
