On Tue, Apr 14, 2020 at 03:22:59PM +0300, Ivan Safonov wrote: > On 4/14/20 2:56 PM, Dan Carpenter wrote: > > On Sun, Apr 12, 2020 at 04:34:08PM +0300, Ivan Safonov wrote: > > > > Remove function rtw_modular64 as all it does is call do_div. > > > > > > This is wrong. Macro do_div(x, y) change first argument x, but > > > rtw_modular64(x, y) preserve it. > > > > > > > + tsf = pmlmeext->TSFValue - do_div(pmlmeext->TSFValue, (pmlmeinfo->bcn_interval*1024)) - 1024; /* us */ > > > > > > rounddown(pmlmeext->TSFValue, pmlmeinfo->bcn_interval * 1024) - 1024 > > > is a better replacement for > > > > You're absolutely correct that the patch is buggy, but I'm not sure that > > rounddown() is what we want. > > > > rtw_modular64() took the MOD of x. So it should be something like: > > > > tsf = pmlmeext->TSFValue - (pmlmeext->TSFValue % (pmlmeinfo->bcn_interval * 1024)) - 1024; /* us */ > > > > But what the heck is that even??? If pmlmeinfo->bcn_interval is zero > > or one then the subtraction ends up giving us a negative. > > > > regards, > > dan carpenter > > > > 1. pmlmeext->TSFValue can not be negative, because it is uint64_t; > 2. pmlmeext->TSFValue is cyclic value: > https://en.wikipedia.org/wiki/Timing_synchronization_function ; > 3. (rounddown(a, b)) is equal to (a - a % b) by definition. Yeah. You're right. I got mixed up and I misread what you were suggesting. tsf = rounddown(pmlmeext->TSFValue, pmlmeinfo->bcn_interval * 1024) - 1024; regards, dan carpenter _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
