Baytrail not able to enter s0ix

[FIsak]

Hello,

I'm working on a batrail (atom z3735g) based linux board, and I'm not able to enter the low-power s0ix states. The BIOS says s0ix is supported (ACPI_FADT_LOW_POWER_S0 bit 21 set). I have verified that all North Complex and South Complex devices are disabled or in D3 or in D0i3 using pmc_atom and punit_atom. I have also checked that the CPU's enter the C7S-BYT C-state and remains in this state for a certain time (> 400ms). What else can block s0ix ? Any idea would be really appreciated since I have worked on this problem for a certain time.

Thanks,

Frode

[Adolfo_S_Intel]

Hello Frode

Could you please provide the following information:

1) What Linux distribution are you using? A know distro or you are creating your own Distribution

2) If you are creating your own distribution please indicate the Kernel version that you are using also indicate if you performed any modification to the kernel

3) If using your own distribution: Please indicate if the issue can be replicated with a Linux mainstream flavor: Fedora, Ubuntu, Debian, etc.

3)Is it possible for testing purposes to replicate this under a Windows Operating System?

I will be waiting for your feedback.

Best Regards,

Adolfo Sanchez

[FIsak]

Hello AdolfoS

I'm using a yocto build with kernel 4.1.8 (git://git.yoctoproject.org/linux-yocto-4.1.git). I have also tried a 3.14 kernel for a baytrail tablet from https://github.com/android-ia/device_intel_gmin-kernel GitHub - android-ia/device_intel_gmin-kernel.

The modifications to the kernel are quite minimal, basically adding the axp288 PMIC driver and the rtl8723bs wifi driver.

With both kernels it was impossible to enter s0ix.

Unfortunately it will eb very difficult to try Windows.

Is there a checklist to go through if s0ix is not working ?

Thanks,

Frode

[CarlosAM_INTEL]

Hello Frode,

Thank you for contacting Intel Embedded Community.

In order to help you please address your questions to the https://www-ssl.intel.com/content/www/us/en/forms/intelligent-systems/get-help-external.html Embedded Design Assistance, where you be connected with a representative in your area, who could possibly help with your questions. Because unfortunately the Bay Trail -T Z37xx is on the "off-roadmap" and its support is for limited manufacturers. For this reason, this processor is unsupported through this channel. Click on http://ark.intel.com/products/series/76761/Intel-Atom-Processor-Z3700-Series this link to learn more about the specifications of the Z37xx family.

Best Regards,

Carlos_A.