Messages in this thread | | | Date | Sat, 17 May 2014 23:09:40 +0200 | From | Jean Delvare <> | Subject | Re: Dell Latitude E6440 & i8k |
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On Sat, 17 May 2014 08:25:38 -0700, Guenter Roeck wrote: > On 05/16/2014 12:11 PM, Jean Delvare wrote: > > Load the i8k driver with fan_mult=1. > > Would it make sense to change the default multiplier to 1 ? > Lots of people have problems with it, and trying to figure out > affected machines one by one would be an all but impossible task.
That would cause a regression on many (presumably older) machines. I doubt this is acceptable. One option would be to use the ACPI year to change the default, if indeed all new machines need fan_mult=1. I don't know if this is the case.
One this I had in mind was auto-detecting the scaling factor. AFAIK only 30 and 1 are possible values, so any value above ~300 would imply scaling factor of 1 (30 would make it > 9000 RPM which is unrealistic.) But I don't know if we can actually do that, as such a simple heuristic could easily fail is the fan is stopped (30 * 0 == 1 * 0) or if the returned raw speed is temporarily unreliable for whatever reason.
I have to admit that working on a reverse engineered driver for hardware I don't even have isn't quite at the top of my to-do list.
-- Jean Delvare SUSE L3 Support
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