Hi, On 11/06/2021 09:45, Daniel Lezcano wrote: > On 11/06/2021 09:30, Nick Xie wrote: >> Hello Neil, >> >> >> Neil Armstrong <narmstrong@xxxxxxxxxxxx> 于2021年6月11日周五 下午3:15写道： >>> >>> Hi, >>> >>> On 11/06/2021 08:54, Nick Xie wrote: >>>> Hello Neil, >>>> >>>> The MCU FAN won't work until the temperature reach to 80 degree centigrade, >>>> Do you think the temperature is too high? >>> >>> I think 80 is tool high, but I fear 50 is way too low, but if you think 50 is OK after you ran some tests, just add it to the commit log and it's ok for me. >> >> I think it is OK, we use it for a long time. > > 50°C sounds like normal temperature with regular load. That means the > fan will be switched on most of the time when the board is used. > > And this change may be put in regard with the other trip points in the > common DT. For instance, enable the fan when reaching 80°C but set the > passive trip point to 75°C instead of 85°C. > > All that depends on the hardware characteristics and TDP which are in > the TRM normally. > I don't think such data exist in the datasheet or other public document, but the vendor source tree sets: - passive: 75°C - hot 85°C - critical 110°C we set upstream: - passive: 85°C - hot 95°C - critical 110°C so maybe we should lower the passive & hot trip points, then the FAN 80°C trip point would be ok now according to Daniel's explanation. Neil
