Thanks, I will include fixes in v2 of the patches. By the way, I'd like to mention that Jan is my colleague. Václav pá 5. 3. 2021 v 13:08 odesílatel Jan Kundrát <jan.kundrat@xxxxxxxxx> napsal: > > > @@ -285,6 +295,9 @@ static int max31790_write_fan(struct device > > *dev, u32 attr, int channel, > > MAX31790_REG_FAN_CONFIG(channel), > > data->fan_config[channel]); > > break; > > + case hwmon_fan_pulses: > > + data->pulses[channel] = val; > > + break; > > This needs input validation, otherwise it's possible to write 0 in there > and you get a division-by-zero in the kernel context: > > [102109.999968] Division by zero in kernel. > [102110.003917] CPU: 1 PID: 27590 Comm: cat Not tainted 5.9.3-cla-cfb #42 > [102110.010462] Hardware name: Marvell Armada 380/385 (Device Tree) > [102110.016497] [<c010f16c>] (unwind_backtrace) from [<c010ae40>] > (show_stack+0x10/0x14) > [102110.024355] [<c010ae40>] (show_stack) from [<c083ba30>] > (dump_stack+0x94/0xa8) > [102110.031689] [<c083ba30>] (dump_stack) from [<c083a3fc>] > (Ldiv0+0x8/0x2c) > [102110.038499] [<c083a3fc>] (Ldiv0) from [<c064c1ac>] > (max31790_read+0x174/0x204) > [102110.045836] [<c064c1ac>] (max31790_read) from [<c0646fdc>] > (hwmon_attr_show+0x44/0x138) > ... > > A similar error can also happen when setting the fan speed to 0 RPM. > That's, however, not an error caused by this patch series AFAIK. I *think* > that RPM_TO_REG should be changed to check if `rpm` is 0, and if so, set > the register directly to the maximal value of 0x7ff (in another patch). > > With kind regards, > Jan