Messages in this thread | | | Date | Mon, 04 Mar 2013 13:29:53 +0100 | From | Roberto Oppedisano <> | Subject | Re: regression in linux 3.7 - fan speed at 100% after suspend/resume at 100% |
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Il 03/03/2013 01:22, Ville Syrjala ha scritto: > Roberto Oppedisano <roberto.oppedisano <at> gmail.com> writes: > >> Hello, >> with recent kernels after a suspend/resume cycle on my laptop (HP >> 6730b) the fans stays at full speed. > I too have been hit by this regression w/ a HP Compaq NC6000 laptop. > > >From what I can tell 3.7.x gets confused about trip points after resume. Based > on the information in sysfs, it seems to always think that the CPU temp > 65C, > when in fact it's usually 40C or so. Loading the CPU enough to rise the > temperature past the trip point where the kernel thinks we're at seems to > re-synchronize the kernel's reality with the firmware's reality. On a few > occasions however the fan did stop, but the trip points were still confused the > same way. So what happened is that the fan didn't come back to life until I hit > the next higher trip point at 80C. Under normal conditions I've never reached > the 80C trip point on this laptop. > > I also tried this tree: > git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux.git next > $ git describe > v3.8-rc2-72-gf5b6d45 > > Sadly I must report that it's even worse than 3.7. Even without any > suspend/resume cycles, the system gets confused. When I heat up the CPU the fan > comes on correctly and speeds up as the temperature rises. Unfortunately when > the temperature drops the fan doesn't slow down at all. So once I hit a high > trip point the fan stays at that speed forever.
I'm running now with:
$ git describe v3.9-rc1
and it seem that the behaviour of my laptop is similar to yours. Also, immediately after a suspend/resume cycle, the fan speed goes down, and again the speeds correctly goes up as the temperature rises, but when the temperature drops the fan doesn't slow.
Now the suspend/resume cycle seems almost unrelated with the issue (except for the fan speed reset at resume).
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