Re: Suspend/resume with FTRACE enabled doesnât work anymore

From: Paul Menzel
Date: Wed Jan 17 2018 - 10:20:09 EST


Dear Linux folks,


On 01/17/18 15:20, Paul Menzel wrote:

Testing Linux 4.15-rc8 on a Lenovo T60 (32 bit) and Dell XPS 13 9360 (64 bit) suspend to and resume from ACPI S3 doesnât work anymore. `./sleepgraph.py -config config/suspend-callgraph.cfg` [1] is used to enable the FTRACE framework.

On the Lenovo T60 the system seems to enter ACPI S3 state just fine, but doesnât wake up.

On the Dell XPS 13 9360 the system doesnât enter ACPI S3 and just freezes with the display still on, and the messages below.

```
[â]
INITIALIZING FTRACE...
Setting trace buffers to 3145728 kB (786432 kB per cpu)
```

Please find the configuration file used for the Lenovo T60 attached.

I first thought it might be related to the UBSAN enabled, but itâs not it.

Here the results for the Dell XPS 13 9360.

Trying Linux 4.13.0-26-generic shipped with Ubuntu 16.04 everything works as expected with `sleepgraph`. The system suspends and resumes. (Though it wakes up before the power button LED turns off.)

Using their mainline Linux kernel 4.15-rc8 build from [1], Linux 4.15-rc8 also freezes during suspend as originally reported.


Kind regards,

Paul


[1] https://01.org/suspendresume
[2] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15-rc8/

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