Messages in this thread | | | Date | Mon, 4 Mar 2013 14:25:21 +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 04/03/2013 13:29, Roberto Oppedisano ha scritto: > 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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