https://bugzilla.kernel.org/show_bug.cgi?id=56591

           Summary: HP/Compaq NC6000 fan speed regression on 3.7+
           Product: ACPI
           Version: 2.5
    Kernel Version: 3.7+
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Power-Thermal
        AssignedTo: acpi_power-ther...@kernel-bugs.osdl.org
        ReportedBy: syrj...@sci.fi
                CC: rui.zh...@intel.com
        Regression: Yes


Created an attachment (id=98531)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=98531)
Logs and dumps from 3.7.10 and 3.9-rc6 kernels

There's a regression in thermal subsystem in 3.7 kernel, which results in fan
speed staying after during resume.

Other people have seen the problem, although it may be that the exact nature of
the bug is a bit different between different machines.

Here are the mailing list references:
https://lkml.org/lkml/2013/3/2/171
https://lkml.org/lkml/2013/4/13/142

For me on 3.7.10 the symptoms of the bug depend on whether I resume the laptop
when it's totally cooled down, or still warm. When the bug occurs, the reported
temperature somehow goes out of sync with the trip points, and the cooling
device cur_state doesn't always match the fan speed.

On 3.9-rc6, there's actually another regression, which causes the fan speed to
misbehave already without any suspend/resume cycles. What happens is that the
fan speeds up when the temperature rises, but when the temperature comes back
down, the fan doesn't slow down. When cooling down, the temperature of the trip
points does seem to change due to hysteresis, so some activity happens when the
trip points are reached, but somehow the cooling devices don't get turned off.
The cooling device cur_state accurately reflects the fan speed in this case.

I also tested
git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux.git thermal
but it appears to behave exactly like 3.9-rc6.

I've attached a tarball with logs from both bug scenarios on a 3.7.10 kernel.
I've included logs from a 3.9-rc6 kernel as well, but as stated you don't
actually need to suspend/resume to trigger the misbehavior on 3.9-rc6. The
"desc.txt" files inside the tarball describe the steps I took when I collected
the logs. The tarball also contains acpidump output.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.

------------------------------------------------------------------------------
Precog is a next-generation analytics platform capable of advanced
analytics on semi-structured data. The platform includes APIs for building
apps and a phenomenal toolset for data science. Developers can use
our toolset for easy data analysis & visualization. Get a free account!
http://www2.precog.com/precogplatform/slashdotnewsletter
_______________________________________________
acpi-bugzilla mailing list
acpi-bugzilla@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla

Reply via email to