On Wed, 19 Dec 2012 06:40:15 -0800 Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > Commit 263a523 fixes a warning seen with W=1 due to change in > DIV_ROUND_CLOSEST. Unfortunately, the C compiler converts divide operations > with unsigned divisors to unsigned, even if the dividend is signed and > negative (for example, -10 / 5U = 858993457). The C standard says "If one > operand has unsigned int type, the other operand is converted to unsigned > int", so the compiler is not to blame. > As a result, DIV_ROUND_CLOSEST(0, 2U) and similar operations now return > bad values, since the automatic conversion of expressions such as "0 - 2U/2" > to unsigned was not taken into account. > > Fix by checking for the divisor variable type when deciding which operation > to perform. This fixes DIV_ROUND_CLOSEST(0, 2U), but still returns bad values > for negative dividends divided by unsigned divisors. Mark the latter case as > unsupported. The changelog didn't describe the end-user visible effects of the bug. Please always include this information. Because... The patch is applicable to 3.7.x. Should we backport it? _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
