On Wed, 2019-02-20 at 10:56 -0700, Nathan Chancellor wrote: > On Wed, Feb 20, 2019 at 11:51:34AM +0100, Arnd Bergmann wrote: > > On Tue, Feb 19, 2019 at 7:22 PM Nathan Chancellor > > <natechancellor@xxxxxxxxx> wrote: > > > diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ftm- > > > initiator.c b/drivers/net/wireless/intel/iwlwifi/mvm/ftm- > > > initiator.c > > > index e9822a3ec373..92b22250eb7d 100644 > > > --- a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c > > > +++ b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c > > > @@ -462,7 +462,7 @@ static void iwl_mvm_debug_range_resp(struct > > > iwl_mvm *mvm, u8 index, > > > { > > > s64 rtt_avg = res->ftm.rtt_avg * 100; > > > > > > - do_div(rtt_avg, 6666); > > > + div64_s64(rtt_avg, 6666); > > > > This is wrong: div64_s64 does not modify its argument like > > do_div(), but > > it returns the result instead. You also don't want to divide by a > > 64-bit > > value when the second argument is a small constant. > > > > I think the correct way should be > > > > s64 rtt_avg = div_s64(res->ftm.rtt_avg * 100, 6666); > > > > If you know that the value is positive, using unsigned types > > and div_u64() would be slightly faster. > > > > Arnd > > Thanks for the review and explanation, Arnd. > > Luca, could you drop this version so I can resend it? Sure, please do! I already applied this internally, but I can just fix it with your new patch and that will be squashed before being sent upstream, so it will look like your second patch. -- Cheers, Luca.