i.MX ProcessorsのトピックRe: IMX8QM-MEK Power Management difference between Linux and Android

IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Fri, 26 Jun 2020 02:02:04 GMT

Dear NXP,

I got observation when I try to send suspend-to-ram command ( echo mem > /sys/power/state ) from Android and Linux

Suspend to Ram in Android OS,

L4.14.98

# echo mem > /sys/power/state

Application Processor going to suspend and resumed automatically

Suspend to Ram in Linux OS,

L4.14.78 & L4.14.98

# echo mem > /sys/power/state

Application Processor going to suspend and wait for user press power key

Will you please give me the configuration or implementation to achieve the Linux level in Android ?

Thanks & Regards,

VinothS,

Re: IMX8QM-MEK Power Management difference between Linux and Android

igorpadykov — Fri, 26 Jun 2020 04:20:58 GMT

Hi Vinoth

for Android supported power management one can refer to

sect.8.9 Power state configuration attached Android Guide.

from NXP Android documentation on link

Android OS for i.MX Applications Processors | NXP

Best regards
igor
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Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Fri, 26 Jun 2020 04:40:20 GMT

Hi Igore,

Thank you for the quick reply. I checked the document and thank you for the document.

I needs to send power 1 2 (=> power 1 2) from M4 console to suspend Application Processor , Am I right ?

Thanks & Regards,

VinothS,

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Fri, 26 Jun 2020 07:05:09 GMT

Hi igorpadykov‌

=> power 1 2

I tried Power control from car MCU console

is working, But, Sometimes the system wakes up by itself.

	Power control from car MCU console	Power control from car2 AP console	Comment
suspend	power 1 2	echo "1 2" > /sys/devices/ platform/vehicle-dummy/ power_req	The system disconnects from BT, waits for all tasks to be done, and then enter suspend mode. Press the power-on key to wake up the system. BT is connected again. Sometimes the system wakes up by itself.

Is there any possible to disable system wake up ?

Thanks & Regards,

VinothS,

Re: IMX8QM-MEK Power Management difference between Linux and Android

igorpadykov — Fri, 26 Jun 2020 10:37:05 GMT

Hi Vinoth

one can look at power management differencies between android and linux

Linux Kernel and Android Suspend/Resume -blog archive

Best regards
igor

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Fri, 03 Jul 2020 04:00:13 GMT

Hi igorpadykov‌

I validate the Linux L4.14.98 in imx8qm Mek board. There is no auto wake-up.

I compared the Linux pm driver source with Android 9 automotive (L4.14.98) look like both are same.

Why android and Linux behaving differently when I write the power sate "echo mem > /sys/power/state " ?

Thanks & Regards,

VinothS

Re: IMX8QM-MEK Power Management difference between Linux and Android

igorpadykov — Fri, 03 Jul 2020 04:30:21 GMT

Hi VinothS

>Why android and Linux behaving differently when I write the power sate "echo mem > /sys/power/state " ?

because power management is different in linux and android as described below

Linux Kernel and Android Suspend/Resume -blog archive

Best regards
igor

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Fri, 03 Jul 2020 05:57:28 GMT

Thank you Igor for your quick reply,

Is it possible to configure Linux power management in Android ?

Thanks & Regards,

VinothS,

Re: IMX8QM-MEK Power Management difference between Linux and Android

igorpadykov — Fri, 03 Jul 2020 06:30:06 GMT

Hi VinothS

this is general android question, suggest to post it on android forums:

Learn about our Developer community programs | Google Developers

Best regards
igor

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Fri, 03 Jul 2020 06:43:16 GMT

Thank you Igor for the reply.

Thanks & Regards,

VinothS,

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Sat, 18 Jul 2020 02:27:08 GMT

Finally I found wake-up API from power driver and disable it for disabling the auto wakeup.

Regards,

VinothS,

Re: IMX8QM-MEK Power Management difference between Linux and Android

smathe25 — Thu, 06 Aug 2020 04:48:05 GMT

Hi vinothkumars‌

Could you specify the driver you updated and changes you made to disable auto wake up.

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Thu, 06 Aug 2020 04:56:54 GMT

Sebimohan Mathew

Find my attachment.

Regards,

Vinoth S,

Re: IMX8QM-MEK Power Management difference between Linux and Android

smathe25 — Thu, 06 Aug 2020 05:35:14 GMT

Thank you so much vinothkumars‌

Have you ever tried GPIO pad wake up with some specific GPIO?

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Thu, 06 Aug 2020 05:52:53 GMT

Hi Sebimohan Mathew

I never tried with GPIO. But, some default wake-up already present.

Wake up done by following,

A53 debug UART
Power Key

WAKE-UP

1. BUTTON

By pressing the power-key SW3 (0.5s)

2. DEBUG UART

Enable debug UART wake-up

# cat ./sys/devices/platform/5a060000.serial/tty/ttyLP0/power/wakeup
disabled

# echo enabled > ./sys/devices/platform/5a060000.serial/tty/ttyLP0/power/wakeup

TO WAKEUP

Press the ENTER Key 2 times

Regards,

Vinoth S,

Re: IMX8QM-MEK Power Management difference between Linux and Android

vinothkumars — Sat, 08 Aug 2020 02:03:51 GMT

Hi Sebimohan Mathew

Please find the document link,

iMX8QM-MEK: SUSPEND AND WAKEUP IN ANDROID 9 AUTOMOTIVE

Best Regards,

Vinoth S,

Re: IMX8QM-MEK Power Management difference between Linux and Android

siva_prabhakara — Mon, 24 Aug 2020 21:05:52 GMT

did u ever get any GPIO wakeup method to work?

Re: IMX8QM-MEK Power Management difference between Linux and Android

smathe25 — Mon, 24 Aug 2020 23:42:24 GMT

Follow this: How to add iMX8QXP PAD（GPIO) Wakeup . This worked for me