Em Mon, 29 Apr 2024 15:05:05 +0000
Ricardo Ribalda <ribalda@xxxxxxxxxxxx> escreveu:
> We do not expect the sample_freq to be over 613MHz.
>
> 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.
>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> drivers/media/dvb-frontends/tda10048.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/dvb-frontends/tda10048.c b/drivers/media/dvb-frontends/tda10048.c
> index 3e725cdcc66b..1886f733dbbf 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;
> + u32 z;
> + u64 t;
>
> dprintk(1, "%s()\n", __func__);
>
> @@ -341,6 +342,7 @@ 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 under 613MHz */
Are you sure about that? Some DVB devices have very high frequency
clocks, specially if they're also used for satellite, so I can't
be sure by just looking at the driver's code.
Also, we had already a bunch of regressions with "fixes" like this
that actually broke frontend drivers.
If you're sure, please add a note at the description mentioning
on what part of the datasheet you got it.
Otherwise, let's stick with the current code and address cocci
warning on a different way.
Regards,
Mauro
PS.: I partially applied this patch series. I left a few
patches out of the merge to let other people review/comment
(and/or for me to take a deeper look later on).
Regards,
Mauro
