ASUS PU551LD, fan stuck at full speed after waking up from S3

ASUS PU551LD, fan stuck at full speed after waking up from S3

[Martin Herkt]

My ASUS PU551LD laptop has a problem with its fan state when resuming from S3. 
In particular, the fan goes to full speed a second or two after waking up and 
cannot be reset without turning off the laptop. For example, rebooting to 
Windows and doing a suspend/resume cycle while the fan is in bad state will 
not reset it. I have observed this behavior with all kernel versions I have 
used on this laptop (oldest being 3.16, newest 4.1-rc5).

sensors(1) does not show any fans, but asus-nb-wmi exposes 
/sys/class/hwmon/hwmon2/pwm1, which shows values like 85 during normal 
operation but goes to the expected 255 when the fan is running at full speed 
after waking up from S3.

acpidump output: https://0x0.st/9Z.out

Not being a kernel dev (but knowing C), what can I do to help fix this issue?

Re: ASUS PU551LD, fan stuck at full speed after waking up from S3

[Rafael J. Wysocki]

On Friday, May 29, 2015 01:51:57 PM Martin Herkt wrote:
> My ASUS PU551LD laptop has a problem with its fan state when resuming from S3. 
> In particular, the fan goes to full speed a second or two after waking up and 
> cannot be reset without turning off the laptop. For example, rebooting to 
> Windows and doing a suspend/resume cycle while the fan is in bad state will 
> not reset it. I have observed this behavior with all kernel versions I have 
> used on this laptop (oldest being 3.16, newest 4.1-rc5).
> 
> sensors(1) does not show any fans, but asus-nb-wmi exposes 
> /sys/class/hwmon/hwmon2/pwm1, which shows values like 85 during normal 
> operation but goes to the expected 255 when the fan is running at full speed 
> after waking up from S3.

Can you please check if applying the patch at

https://patchwork.kernel.org/patch/6451241/

on top of 4.1-rc5 makes any difference?


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: ASUS PU551LD, fan stuck at full speed after waking up from S3

[Martin Herkt]

On Saturday 30 May 2015 14:14:06 Rafael J. Wysocki wrote:
> On Friday, May 29, 2015 01:51:57 PM Martin Herkt wrote:
> > My ASUS PU551LD laptop has a problem with its fan state when resuming from
> > S3. In particular, the fan goes to full speed a second or two after
> > waking up and cannot be reset without turning off the laptop. For
> > example, rebooting to Windows and doing a suspend/resume cycle while the
> > fan is in bad state will not reset it. I have observed this behavior with
> > all kernel versions I have used on this laptop (oldest being 3.16, newest
> > 4.1-rc5).
> > 
> > sensors(1) does not show any fans, but asus-nb-wmi exposes
> > /sys/class/hwmon/hwmon2/pwm1, which shows values like 85 during normal
> > operation but goes to the expected 255 when the fan is running at full
> > speed after waking up from S3.
> 
> Can you please check if applying the patch at
> 
> https://patchwork.kernel.org/patch/6451241/
> 
> on top of 4.1-rc5 makes any difference?

No, still happens with that patch.