Re: Fans at full speed after resume

[Sonny Rao]

On Tue, May 14, 2013 at 9:29 PM, Zhang Rui <rui.zhang@xxxxxxxxx> wrote:
> On Wed, 2013-05-15 at 12:26 +0800, Zhang Rui wrote:
>> please
>>
>> On Tue, 2013-05-14 at 21:18 -0700, Sonny Rao wrote:
>> > Hi, I've seen a regression in kernels since 3.7 on x86 devices where
>> > the kernel turns the system fans on to max speed after resuming from
>> > ram.  Other people have noticed it as well, for example see
>> > https://bugzilla.redhat.com/show_bug.cgi?id=895276
>> >
>> please check if this is a duplicate of bug
>> https://bugzilla.kernel.org/show_bug.cgi?id=56591
> or you can try 3.10-rc1 to see if the problem still exists or not.

Ok, I patched in the fix from that bugzilla --
928c5edbe6f7cb0d1c71bc2353d091bc5b114fe3
but I'm still seeing the issue, I'll try 3.10-rc1 next

>
> thanks,
> rui
>> > For example on the Samsung 550 Chromebook, we have one thermal zone
>> > and have 5 cooling_devices, 0-4, which correspond to 5 possible fan
>> > speeds.  Under typical idle, only cooling_device4 and maybe
>> > cooling_device3 are active, depending on temperature:
>> >
>> > cat /sys/class/thermal/cooling_device[01234]/cur_state
>> > /sys/class/thermal/thermal_zone0/temp
>> > 0
>> > 0
>> > 0
>> > 0
>> > 1
>> > 57000
>> >
>> > however after a suspend/resume, we see that cooling_devices 0 and 1
>> > become active:
>> > cat /sys/class/thermal/cooling_device[01234]/cur_state
>> > /sys/class/thermal/thermal_zone0/temp
>> > 1
>> > 1
>> > 0
>> > 0
>> > 1
>> > 54000
>> >
>> > and it seems to stay that way, even though the temperature is low
>> > enough that the fan shouldn't be running at that speed.  If I manually
>> > disable cooling_devices 0 and 1 then fan control works normally again.
>> >
>> > I started bisecting it and was able to do so up until this commit:
>> > commit 29b19e250434c6193c8b8e4c34c9c6284dd4f101
>> > Merge: 125c4c7 c072fed
>> > Author:     Len Brown <len.brown@xxxxxxxxx>
>> > AuthorDate: Tue Oct 9 01:35:52 2012 -0400
>> > Commit:     Len Brown <len.brown@xxxxxxxxx>
>> > CommitDate: Tue Oct 9 01:35:52 2012 -0400
>> >
>> >     Merge branch 'release' of
>> > git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux into
>> > thermal
>> >
>> > unfortunately, I'm not able to successfully do a suspend/resume on the
>> > commits in that merge, so I wasn't able to bisect down to the exact
>> > commit.
>> >
>> > I did confirm that one parent of the merge is okay: commit
>> > 125c4c706b680c7831f0966ff873c1ad0354ec25 idr: rename MAX_LEVEL to
>> > MAX_IDR_LEVEL
>> >
>> > so I think it falls somewhere in this list of commits:
>> > c072fed95c9855a920c114d7fa3351f0f54ea06e...e3f25e6e5836c4790fbe395ff42e241f372d859d
>> >
>> > c072fed9 thermal: Exynos: Fix NULL pointer dereference in
>> > exynos_unregister_thermal()
>> > a4b6fec9 Thermal: Fix bug on cpu_cooling, cooling device's id conflict problem.
>> > 79e093c3 thermal: exynos: Use devm_* functions
>> > 17be868e ARM: exynos: add thermal sensor driver platform data support
>> > 7e0b55e6 thermal: exynos: register the tmu sensor with the kernel thermal layer
>> > f22d9c03c thermal: exynos5: add exynos5250 thermal sensor driver support
>> > c48cbba6 hwmon: exynos4: move thermal sensor driver to driver/thermal directory
>> > 02361418 thermal: add generic cpufreq cooling implementation
>> > a7a3b8c8 Fix a build error.
>> > 204dd1d3 thermal: Fix potential NULL pointer accesses
>> > 1e426ffdd thermal: add Renesas R-Car thermal sensor support
>> > 79a49168 thermal: fix potential out-of-bounds memory access
>> > f4a821ce6 Thermal: Introduce locking for cdev.thermal_instances list.
>> > 908b9fb79 Thermal: Unify the code for both active and passive cooling
>> > ce119f832 Thermal: Introduce simple arbitrator for setting device cooling state
>> > b5e4ae62 Thermal: List thermal_instance in thermal_cooling_device.
>> > cddf31b3b Thermal: Rename thermal_instance.node to thermal_instance.tz_node.
>> > 2d374139 Thermal: Rename thermal_zone_device.cooling_devices
>> > b81b6ba3 Thermal: rename structure thermal_cooling_device_instance to
>> > thermal_instance
>> > 4ae46befb Thermal: Introduce thermal_zone_trip_update()
>> > 1b7ddb84 Thermal: Remove tc1/tc2 in generic thermal layer.
>> > 601f3d424 Thermal: Introduce .get_trend() callback.
>> > 9d99842f9 Thermal: set upper and lower limits
>> > 74051ba5 Thermal: Introduce cooling states range support
>> >
>> > When I get time, I'll try to rebase those commits onto the IDR commit
>> > and see if I can get a better bisect.  Any insights into the problem
>> > would be appreciated, thanks.
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pm" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/