On Wed, Dec 11, 2024 at 01:51:31PM +0200, Andy Shevchenko wrote: > On Wed, Dec 11, 2024 at 11:32 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > > > The problem is this multiply in tps6594_rtc_set_offset() > > > > tmp = offset * TICKS_PER_HOUR; > > > > The "tmp" variable is an s64 but "offset" is a long in the > > (-277774)-277774 range. On 32bit systems a long can hold numbers up to > > approximately two billion. The number of TICKS_PER_HOUR is really large, > > (32768 * 3600) or roughly a hundred million. When you start multiplying > > by a hundred million it doesn't take long to overflow the two billion > > mark. > > > > Probably the safest way to fix this is to change the type of > > TICKS_PER_HOUR to long long because it's such a large number. > > ... > > > -#define TICKS_PER_HOUR (32768 * 3600) > > +#define TICKS_PER_HOUR (32768 * 3600LL) > > Hmm... And why signed? It needs to be signed for negatives. That's deliberate. regards, dan carpenter
