Re: S3 resume issues

[Malcolm Crossley <malcolm.crossley@citrix.com>]

Hi Ben,

On 02/01/13 13:08, Ben Guthro wrote:
> I'm starting a new thread on this, to attempt to not confuse this 
> issue, with the other S3 issue reported by Marek Marczykowski against 4.1
> If you prefer I continue that thread instead, please let me know, and 
> I will be happy to do so.
>
> Some background:
> I am attempting to chase down yet another S3 issue in the Xen-4.2 / 
> unstable tree, seen on some (but not all) platforms.
> The particular machine I am able to reproduce it 100% of the time is a 
> Lenovo T430 (Ivy bridge laptop)
>
To help reproduce the issue it would be good to know what Linux kernel 
you were using.

Also, Does Xen-4.1 work on this particular machine? If Xen-4.1 does not 
work, have you confirmed that baremetal suspend resume works? (I'm just 
covering the base's here)

I also notice that the laptop can have NVIDIA optimus technology. Does 
this particular T430 have an Nvidia GPU? Is there a way to force disable 
the NVIDIA GPU in the BIOS, this may help with displaying resume 
progress via the display.
> The symptoms of the failure are that it suspends just fine, but does 
> not resume.
> When attempting to resume, by pressing the power button - the disk LED 
> flashes, and the CDROM activity LED flashes, but then the system seems 
> to put itsself back to sleep, as the power LED goes back to pulsing
> Note that the soft pulsing LED is distinctly different from the crash 
> LED blink rate.
Is there any sign of the video POSTING (flickering screen etc) ?
>
> I have tried a number of the tricks Jan suggested to me the last time 
> we were down this path - so far to no success.
> The failure seems to be happening so soon in the resume process, that 
> there is not yet a console available.
>
> I have resorted to putting BUG() in the code directly in the resume 
> path, in an attempt to understand what is going on - since there seems 
> to be something in this path that I don't fully understand.
>
> In xen/arch/x86/acpi/power.c - acpi_enter_sleep_state() seems to be 
> the code that actually puts the processor into S3.
> If I put a BUG() directly before the return of this function - I never 
> seem to reach this. It continues to pulse the power LED, as described 
> above.
> I would have expected a hypervisor crash upon attempting to wake up 
> the system.
>
The actual wakeup vector is wakeup_start in xen/arch/x86/boot/wakeup.S

Malcolm