[U-Boot] [PATCH v2 00/22] x86: Add ACPI S3 resume support

[Bin Meng]

Hi Stefan,

On Tue, Apr 25, 2017 at 7:11 PM, Stefan Roese <sr at denx.de> wrote:
> Hi Bin,
>
> On 25.04.2017 11:34, Bin Meng wrote:
>
> <snip>
>
>>>> What do you mean by "display
>>>> stays in power safe mode"? Is it a black screen, or is it just
>>>> U-Boot's video output screen?
>>>
>>> Blank screen and the monitor does not wake up from power-safe
>>> mode. I see the log on the serial console, since I've changed the
>>> environment (stdio) to not use the LCD as the console in U-Boot.
>>> U-Boot uses the console as a splash screen instead.
>>>
>>
>> Since you were seeing black screen I guess your U-Boot was not running
>> the VGA BIOS for the Intel Baytrail IGD?
>
> My U-Boot configuration runs the VGA BIOS via the "preboot" env
> command:
>
> => printenv preboot
> preboot=load scsi 0:${ubuntu_part} ${loadaddr} /boot/logo/logo.bmp;bmp display ${loadaddr}
>
>> The LCD driver is not the
>> Intel i915 graphics driver?
>
> In Linux it is. But in the resume case, the preboot env command is
> not run, so this explains why the screen is not initialized by
> U-Boot (again).
>

[snip]

> [  107.386512] calling  parport_pc.888+ @ 2365, parent: platform
> [  107.392954] call parport_pc.888+ returned 0 after 0 usecs
> [  107.399026] calling  coretemp.0+ @ 2365, parent: platform
> [  107.405077] call coretemp.0+ returned 0 after 0 usecs
> [  107.410764] calling  pxa2xx-spi.0+ @ 2365, parent: 0000:00:1e.5
> [  107.417408] call pxa2xx-spi.0+ returned 0 after 9 usecs
> [  107.423277] calling  input5::numlock+ @ 2365, parent: input5
> [  107.429624] call input5::numlock+ returned 0 after 0 usecs
> [  107.435773] calling  input5::capslock+ @ 2365, parent: input5
> [  107.442221] call input5::capslock+ returned 0 after 0 usecs
> [  107.448473] calling  input5::scrolllock+ @ 2365, parent: input5
> [  107.455112] call input5::scrolllock+ returned 0 after 0 usecs
> [  107.461553] calling  iTCO_wdt.0.auto+ @ 2365, parent: 0000:00:1f.0
> [  107.468484] call iTCO_wdt.0.auto+ returned 0 after 0 usecs
> [  107.474653] PM: resume of devices complete after 1876.472 msecs
> [  107.663708] PM: Finishing wakeup.
> [  107.667482] Restarting tasks ... done.
> [  109.225751] igb 0000:04:00.0 ens3: igb: ens3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
>
> I can't reproduce the resume problem with this pm_async setting
> any more. At least all my 10 attempts were successful now.

Thanks for testing. On my side, I was able to reproduce the unstable
suspend/resume with Ubuntu 16.04 several times on Minnowmax. Looks
there are some timing issues (pm_async) and with the Intel i915
driver. Sometimes kernel even does not suspend correctly (kernel oops
in the i915 driver). I will have a look.

Regards,
Bin