[AM437x] Confirm Kernel Perfromance

Kaka

Guru 24520 points

Hi community member,

Please let me confirm the following question.

[Question]

Would you please explain about "suspend" on wake up time on the following URL?

Does it mean suspend mode on linux?

If you have any question, please let me know.

Best regards.

Kaka

over 10 years ago

0 Yordan Kovachev over 10 years ago

TI__Guru**** 161600 points

Hi,

Could you please specify which section of the guide you refer to? is it Wakeup times (processors.wiki.ti.com/.../Sitara_Linux_SDK_Kernel_Performance_Guide), specifically table Wakeup times with different resume events?

If so then, yes suspend means: suspend mode on linux.

Best Regards,
Yordan

0 Kaka over 10 years ago in reply to Yordan Kovachev

Guru 24520 points

Hi Yordan,

Thank you for your response.

Yes, I pointed out the "Wakeup times with different resume events".

Best regards.
Kaka

0 Kaka over 10 years ago in reply to Kaka

Guru 24520 points

Hi Yordan,

Please let me confirm one more question.

When the system is suspend mode, what is the status of AM437x? Deep sleep? RTC-only?

Best regards.
Kaka

0 Yordan Kovachev over 10 years ago in reply to Kaka

TI__Guru**** 161600 points

Hi Kaka,

Upone entering suspend mode ( executing echo mem > /sys/power/state) the sequence is as follows:
1. Kernel PM:
- Freeze filesystems, userspace processes
-am33xx_pm_begin: Inform CM3 of intended low power state
-Suspend all drivers through handlers
2. Driver Suspend
-Drivers pm callbacks are responsible for
--Preparing the device for suspend
--Saving peripheral context
--Setting IO Pad config
-omap_device/omap_hwmod handles PRCM control.
3. On device level (SRAM):
-Flush and disable caches
-Put SDRAM into Self-Refresh
-Save EMIF Context and Disable
-Gate MPU Clock
-Execute WFI

So this is equivalent to deep sleep on the evm (& processor)

Best Regards,
Yordan

Processors

Processors forum

[AM437x] Confirm Kernel Perfromance