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Few enhancement ideas

DISCUSSION Amit Kucheria 6 participants 8 messages Jul 13, 2005 – Jul 17, 2005

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#0 lore raw

Hi,

Being our first post to this list, I would like to introduce ourselves as part of the team behind the Nokia 770 (www.nokia.com/770). We have been preoccupied with the product launch, but now we will be able to participate, starting with the Ottawa Linux Symposium.

Team contributions
==================
The Nokia 770 Linux team has made many contributions to the Linux-OMAP port, some of the PM-specific ones being:

- Dynamic tick patch by Tony Lindgren
(http://www.muru.com/linux/dyntick/): Initially for
the OMAP architecture followed by the recent x86 port
- Clock framework for the OMAP architecture - Thanks to Tuukka Tikkanen
- PM-enabling various drivers in the mach-omap tree

The Product
===========
Nokia 770 is powered by an OMAP1710 on a custom board. The device will ship with a 1500mAh battery which will give a continuous browsing use-time (WLAN or Bluetooth) of 3hrs. The device needed to be instant-ON, so we have used run-time power management. This gives us an official 'standby-time' of 7 days. All the drivers make extensive use of the clock framework and release clocks when peripheral is not in use.

Interests
=========
Here are a few ideas that we are planning to investigate in order to address shortcomings in the current PM model with respect to system-wide PM:

- Regulator framework: similar to clock framework HAL
- Generic framework for system-wide constraints: to handle constraints outside bus control
- PM framework: Enhance PM framework to allow flexible policy control. Like DPM?
- User space API: Requires study

Are these ideas of interest to the PM community or Nokia-specific?

Contacts
========
We will be in Ottawa 16.07.05 - 24.07.05. It would be nice to meet others on this list to discuss these ideas further.

Have a good day.

Regards,
Amit

Signature · 2 lines
Amit Kucheria <[email protected]>
Nokia
#1 lore raw
Quoted 4 lines

- PM framework: Enhance PM framework to allow flexible policy control. Like DPM?

Are these ideas of interest to the PM community or Nokia-specific?

No, this is very much interesting to many of us. We were having some lively debates, and then it kind of died out. I suppose that the PM gurus will discuss this at OLS and give us a report.

Signature · 4 lines
Jordan Crouse
Senior Linux Engineer
AMD - Personal Connectivity Solutions Group
<www.amd.com/embeddedprocessors>
#2 lore raw
In reply to Amit Kucheria
Quoted 8 lines

The Product
===========
Nokia 770 is powered by an OMAP1710 on a custom board. The device will ship with a 1500mAh battery which will give a continuous browsing use-time (WLAN or Bluetooth) of 3hrs. The device needed to be instant-ON, so we have used run-time power management. This gives us an official 'standby-time' of 7 days. All the drivers make extensive use of the clock framework and release clocks when peripheral is not in use.

... and all that running Linux! The last rumor I heard was that it might base on the 2.6.12 kernel. I look forward to seeing one of these, so I'll know for sure!

For those unfamiliar with OMAP, http://linux.omap.com is a place to start ... there's a Linux-OMAP mailing list and patches (such as 2.6.13-rc1-omap1) in a GIT repository, many of which have made their way into kernel.org releases. It's a family of ARM SOC processors that's very power-efficient.

Quoted 7 lines

Interests
=========
Here are a few ideas that we are planning to investigate in order to address shortcomings in the current PM model with respect to system-wide PM:

- Regulator framework: similar to clock framework HAL

Perhaps you could elaborate in a separate email thread?

Quoted 7 lines

- Generic framework for system-wide constraints: to handle constraints outside bus control
- PM framework: Enhance PM framework to allow flexible policy control. Like DPM?
- User space API: Requires study

Are these ideas of interest to the PM community or Nokia-specific?

General interest!

I'll be very glad to see a more cross-pollination from that part of the embedded Linux world. Laptops get plenty of attention, but there's more to Linux than that. :)

- Dave

#3 lore raw

Hi,

Quoted 3 lines · On Wed, 2005-07-13 at 11:38 -0700, ext [email protected]…
Quoted 3 lines

The Product
===========
Nokia 770 is powered by an OMAP1710 on a custom board.

[snip]

Quoted 3 lines

... and all that running Linux! The last rumor I heard was that it might base on the 2.6.12 kernel. I look forward to seeing one of these, so I'll know for sure!

Yes, we'll bring some with us.

Quoted 13 lines

For those unfamiliar with OMAP, http://linux.omap.com is a place to start ... there's a Linux-OMAP mailing list and patches (such as 2.6.13-rc1-omap1) in a GIT repository, many of which have made their way into kernel.org releases. It's a family of ARM SOC processors that's very power-efficient.

Quoted 6 lines

Interests
=========
Here are a few ideas that we are planning to investigate in order to address shortcomings in the current PM model with respect to system-wide PM:

Quoted 3 lines
Quoted 1 line

- Regulator framework: similar to clock framework HAL

Perhaps you could elaborate in a separate email thread?

As Amit wrote we've been very busy till now, but we plan to elaborate an articulated proposal

Quoted 16 lines
Quoted 7 lines

- Generic framework for system-wide constraints: to handle constraints outside bus control
- PM framework: Enhance PM framework to allow flexible policy control. Like DPM?
- User space API: Requires study

Are these ideas of interest to the PM community or Nokia-specific?

General interest!

I'll be very glad to see a more cross-pollination from that part of the embedded Linux world. Laptops get plenty of attention, but there's more to Linux than that. :)

- Dave

#4 lore raw
In reply to Amit Kucheria
Quoted 10 lines · Amit Kucheria

The Nokia 770 Linux team has made many contributions to the Linux-OMAP port, some of the PM-specific ones being:

- Dynamic tick patch by Tony Lindgren
(http://www.muru.com/linux/dyntick/): Initially for
the OMAP architecture followed by the recent x86 port
- Clock framework for the OMAP architecture - Thanks to Tuukka Tikkanen ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- PM-enabling various drivers in the mach-omap tree

My thanks to you and Tuukka Tikkanen as well. I took the ARM clock
API framework you developed for the OMAP, hacked it to shreds and got it working on the Freescale i.MX1.

Some clocks on the i.MX1 are always running, so when they're unused,
I elected to spin them down the slowest available speed, saving a bit more power. I also keep a copy of the requested target frequency so that when parent clocks get changed, I can keep the child clocks running as close as possible to the originally requested speed. This is useful for stuff like the I2C bus and audio clocks, and really darned helpful in keeping the console serial port working correctly.

When you were implementing the framework, did you have any thoughts
about where the initial clock frequencies "should" come from? It sounds like a policy issue, and therefore compiling it into the kernel (as you've done in your OMAP implementation) is The Wrong Thing. But it's not at all clear where else it could go.

Again, my thanks. It was tons of help.

Schwab

#5 lore raw

On Thu, 2005-07-14 at 14:56 -0700, ext Leo L. Schwab wrote:
[snip]

Quoted 5 lines

When you were implementing the framework, did you have any thoughts
about where the initial clock frequencies "should" come from? It sounds like a policy issue, and therefore compiling it into the kernel (as you've done in your OMAP implementation) is The Wrong Thing. But it's not at all clear where else it could go.

We agree on that: it looks like a policy and the way to provide the means to configure it is something that should be discussed.

We are still considering a few implementation options.

igor

Quoted 8 lines

Again, my thanks. It was tons of help.

Schwab
_______________________________________________
linux-pm mailing list
[email protected]
https://lists.osdl.org/mailman/listinfo/linux-pm

#6 lore raw
In reply to Amit Kucheria

Hi!

Quoted 4 lines

Being our first post to this list, I would like to introduce ourselves as part of the team behind the Nokia 770 (www.nokia.com/770). We have been preoccupied with the product launch, but now we will be able to participate, starting with the Ottawa Linux Symposium.

That's definitely nice machine...

Quoted 7 lines

The Product
===========
Nokia 770 is powered by an OMAP1710 on a custom board. The device will ship with a 1500mAh battery which will give a continuous browsing use-time (WLAN or Bluetooth) of 3hrs. The device needed to be instant-ON, so we have used run-time power management. This gives us an

Would not suspend-to-RAM be enough? Or does machine need to continue loading pages when it is "turned off"?

Quoted 4 lines

Contacts
========
We will be in Ottawa 16.07.05 - 24.07.05. It would be nice to meet others on this list to discuss these ideas further.

I would like to meet you, if only to see those beasts.

Pavel

Signature · 1 line
teflon -- maybe it is a trademark, but it should not be.
#7 lore raw
Quoted 7 lines · ext Pavel Machek
Quoted 4 lines

Contacts
========
We will be in Ottawa 16.07.05 - 24.07.05. It would be nice to meet others on this list to discuss these ideas further.

I would like to meet you, if only to see those beasts.

Due to airline scheduling and a case of missed flights, we have only just arrived in Ottawa. Maybe we could meet some time before the OLS?

Regards,
Amit

Signature · 2 lines
Amit Kucheria <[email protected]>
Nokia