dm8168 power management

Steven Weng1

Expert 2200 points

Hi All,

From this link : http://processors.wiki.ti.com/index.php/TI81XX_PSP_PM_FAQ

TI816X doesnt support these feature : "Suspend to RAM", "DeepSleep","DVFS","CPUIdle".

Does it is hardware limitation?

Is it possible to implement these feature just like ti814x did ?

Thanks!

BR,

Steven

over 10 years ago

0 Steven Weng1 over 10 years ago

Expert 2200 points

Hi,

Are there any documents talking about TI81xx power management?

Any helps will be appreciate!

Thanks a lot.

Steven

0 Renjith Thomas over 10 years ago in reply to Steven Weng1

Guru 31670 points

Steven,

It should be possible to implement these features like 814x. Other than the technical reference manual, I'm not aware of any particular PM document for DM816x.

0 Holger Eberhard102906 over 9 years ago in reply to Renjith Thomas

Genius 4570 points

Hi,

we also are interested in reducing power consumtion of DM8168.

Does anybody have used CPU Power Management for DM8168 ?

Best regards Holger

0 Pavel Botev over 9 years ago in reply to Holger Eberhard102906

TI__Guru**** 170625 points

Holger,

Refer to the below wiki:

processors.wiki.ti.com/.../TI81XX_PSP_User_Guide

processors.wiki.ti.com/.../AM389x_C6A816x_DM816x_Hardware_Design_Guide

Regards,
Pavel

0 Holger Eberhard102906 over 9 years ago in reply to Pavel Botev

Genius 4570 points

Hi Pavel,
Thanks for infos.
I try to use the kernel configuration options.
But I don't have experience what impact these options have at DM8168.

# CPU Power Management

CONFIG_CPU_FREQ
CONFIG_CPU_FREQ_TABLE
CONFIG_CPU_FREQ_DEBUG
CONFIG_CPU_FREQ_STAT
CONFIG_CPU_FREQ_STAT_DETAILS
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
CONFIG_CPU_FREQ_GOV_PERFORMANCE
CONFIG_CPU_FREQ_GOV_POWERSAVE
CONFIG_CPU_FREQ_GOV_USERSPACE
CONFIG_CPU_FREQ_GOV_ONDEMAND
CONFIG_CPU_FREQ_GOV_CONSERVATIVE
CONFIG_CPU_IDLE
CONFIG_CPU_IDLE_GOV_LADDER
CONFIG_CPU_IDLE_GOV_MENU

Best regards Holger

0 Holger Eberhard102906 over 9 years ago in reply to Holger Eberhard102906

Genius 4570 points

CPU Power Management for DM8168 seems only possible for CONFIG_ARCH_OMAP3 od CONFIG_ARCH_TI814X?
Best regards Holger

0 Pavel Botev over 9 years ago in reply to Holger Eberhard102906

TI__Guru**** 170625 points

Holger,

Holger Eberhard102906 said:
CONFIG_CPU_FREQ
CONFIG_CPU_FREQ_TABLE
CONFIG_CPU_FREQ_DEBUG
CONFIG_CPU_FREQ_STAT
CONFIG_CPU_FREQ_STAT_DETAILS
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
CONFIG_CPU_FREQ_GOV_PERFORMANCE
CONFIG_CPU_FREQ_GOV_POWERSAVE
CONFIG_CPU_FREQ_GOV_USERSPACE
CONFIG_CPU_FREQ_GOV_ONDEMAND
CONFIG_CPU_FREQ_GOV_CONSERVATIVE

I think these are supported only for TI814x device. See the below pointers for more info:

linux-kernel/Documentation/cpu-freq/

Holger Eberhard102906 said:
CONFIG_CPU_IDLE
CONFIG_CPU_IDLE_GOV_LADDER
CONFIG_CPU_IDLE_GOV_MENU

CPUIdle is not supported nor for TI816x neither for TI814x. See the below pointers for more info:

linux-kernel/Documentation/cpuidle/

Regards,
Pavel

0 Holger Eberhard102906 over 9 years ago in reply to Pavel Botev

Genius 4570 points

DM8148 has some useful power features.
It seems that we can not find a way to reduce power of DM8168 if application is running.
What about Operating Performance Point (OPP) - is this applicable for DM8168 ?

0 Pavel Botev over 9 years ago in reply to Holger Eberhard102906

TI__Guru**** 170625 points

Holger,

I can not find OPP info into the DM816x documentation, thus I can state this is not applicable for DM8168.

DM8168 has better performance and more modules/peripherals than the DM8148 device. On the other hand, DM8148 is more power efficient than the DM8168.

Regards,
Pavel

0 Holger Eberhard102906 over 9 years ago in reply to Pavel Botev

Genius 4570 points

Pavel Thanks for Your assessment.

Best regards Holger

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