The datasheet recommends 55MHz frequency sampling, with a max of 69 MHz.
(Kudos to Kosta Stefanov for the calculations).
Replace z with a 32 bit uint, and make the range of the variable
explicit.
Found by cocci:
drivers/media/dvb-frontends/tda10048.c:345:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead.
Reviewed-by: Kosta Stefanov <costa.stephanoff@xxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/dvb-frontends/tda10048.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/media/dvb-frontends/tda10048.c b/drivers/media/dvb-frontends/tda10048.c
index 3e725cdcc66b..1f87eb0dcf2a 100644
--- a/drivers/media/dvb-frontends/tda10048.c
+++ b/drivers/media/dvb-frontends/tda10048.c
@@ -328,7 +328,8 @@ static int tda10048_set_wref(struct dvb_frontend *fe, u32 sample_freq_hz,
u32 bw)
{
struct tda10048_state *state = fe->demodulator_priv;
- u64 t, z;
+ u64 t;
+ u32 z;
dprintk(1, "%s()\n", __func__);
@@ -341,6 +342,11 @@ static int tda10048_set_wref(struct dvb_frontend *fe, u32 sample_freq_hz,
/* t *= 2147483648 on 32bit platforms */
t *= (2048 * 1024);
t *= 1024;
+
+ /*
+ * Sample frequency is typically 55 MHz, with a theoretical maximum of
+ * 69 MHz. With a 32 bit z we have enough accuracy for up to 613 MHz.
+ */
z = 7 * sample_freq_hz;
do_div(t, z);
t += 5;
--
2.47.1.613.gc27f4b7a9f-goog
