Bjorn Helgaas | 1 Sep 01:13 2006
Picon

Re: [RFC][PATCH 1/2] ACPI: Idle Processor PM Improvements

On Wednesday 30 August 2006 13:43, Matthew Garrett wrote:
> That would be helpful. For the One Laptop Per Child project (or whatever 
> it's called today), it would be advantageous to run without acpi.

Out of curiosity, what is the motivation for running without acpi?
It costs a lot to diverge from the mainstream in areas like that,
so there must be a big payoff.  But maybe if OLPC depends on acpi
being smarter about power or code size or whatever, those improvements
could be made and everybody would benefit.
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Matthew Garrett | 1 Sep 01:27 2006

[OLPC-devel] Re: [RFC][PATCH 1/2] ACPI: Idle Processor PM Improvements

On Thu, Aug 31, 2006 at 05:13:20PM -0600, Bjorn Helgaas wrote:

> Out of curiosity, what is the motivation for running without acpi?
> It costs a lot to diverge from the mainstream in areas like that,
> so there must be a big payoff.  But maybe if OLPC depends on acpi
> being smarter about power or code size or whatever, those improvements
> could be made and everybody would benefit.

The current issues are probably the code size and the somewhat 
specialised needs of OLPC. The hardware is interesting in that the 
framebuffer is designed to carry on reading from memory even if the rest 
of the system is in S3. The aim here is to allow the machine to suspend 
when idle while still giving the impression of being alive. It's 
therefore important that the system come out of suspend as quickly as 
possible in order to avoid spoiling that impression, and suspend as 
quickly as possible in order to maximise the power savings. The 
assumption is that parsing AML is something that would add to these time 
periods without providing any significant extra benefit.

Of course, the other main issue is that providing an ACPI platform would 
require us to actually write a set of ACPI tables. The system is running 
Linuxbios, and every kilobyte that's not used by a static table in the 
BIOS is space that could be used for extra functionality.

I think the basic consensus was that ACPI bought us fairly little other 
than the ability to use the existing suspend/resume code, C state 
transitions and battery monitoring, and that replacing the first was 
probably desirable in any case.
--

-- 
Matthew Garrett | mjg59 <at> srcf.ucam.org
(Continue reading)

Zarro Boogs per Child | 1 Sep 02:00 2006

[OLPC-devel] Re: [One Laptop Per Child] #78: Wireless driver sometimes fails to bind to enumerated device

#78: Wireless driver sometimes fails to bind to enumerated device
--------------------+-------------------------------------------------------
 Reporter:  cjb     |        Owner:  marcelo  
     Type:  defect  |       Status:  reopened 
 Priority:  high    |    Milestone:  rev1 beta
Component:  kernel  |   Resolution:           
 Keywords:          |  
--------------------+-------------------------------------------------------
Changes (by cjb):

  * status:  closed => reopened
  * resolution:  fixed =>

Comment:

 I shouldn't have closed this; reopening so that we can debug the deadlock.

--

-- 
Ticket URL: <http://dev.laptop.org/ticket/78#comment:4>
One Laptop Per Child <http://laptop.org/>
Marcelo Tosatti | 1 Sep 02:27 2006
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Re: [OLPC-devel] Re: linker garbage collection

On Thu, Aug 31, 2006 at 02:48:47PM -0700, David Woodhouse wrote:
> On Thu, 2006-08-31 at 14:05 -0300, Marcelo Tosatti wrote:
> > On Thu, Aug 31, 2006 at 08:22:57AM -0700, David Woodhouse wrote:
> > > On Tue, 2006-08-29 at 23:54 -0300, Marcelo Tosatti wrote:
> > > > * Condition CONFIG_GC_SECTIONS on presence of a recent binutils  
> > > 
> > > Er, I missed something -- why does this need a recent binutils? We've
> > > been building kernels with --gc-sections for years, at least on some
> > > platforms.
> > 
> > First, I think its prudent to guarantee that a well behaved version of
> > binutils (wrt. garbage collection) is being used. No?
> 
> Are recent versions of binutils known to misbehave? It's not as if
> --gc-sections is a new thing.

Not that I know, just being (overly) safe.

> > Second reason is the newly added --print-gc-sections option, which:
> 
> ... needs to be a CONFIG option anyway so _that_ CONFIG option can
> require the new binutils.

Agreed.

> > 2) Its very useful for developers to
> > 
> > - Debug breakage caused by gc-section misbehaviour.
> > - Easily check what symbols are being swept.
> 
(Continue reading)

Jim Gettys | 1 Sep 02:30 2006

Re: [OLPC-devel] Re: [RFC][PATCH 1/2] ACPI: Idle Processor PM Improvements

On Thu, 2006-08-31 at 17:13 -0600, Bjorn Helgaas wrote:
> On Wednesday 30 August 2006 13:43, Matthew Garrett wrote:
> > That would be helpful. For the One Laptop Per Child project (or whatever 
> > it's called today), it would be advantageous to run without acpi.
> 
> Out of curiosity, what is the motivation for running without acpi?
> It costs a lot to diverge from the mainstream in areas like that,
> so there must be a big payoff.  But maybe if OLPC depends on acpi
> being smarter about power or code size or whatever, those improvements
> could be made and everybody would benefit.

Good question; I see Matthew beat me to part of the explanation, but
here is more detail:

Our screen consumes of order 1/10th the power of a conventional flat
panel, and can consume a half watt or so (yes, we now have working
screens; this is not mythological hardware; I got my own personal first
hand look at prototype display running this afternoon :-); I always do
line new toys...).  

Even though the base machine may take only a couple watts of power
(Geode GX + the rest of the base logic), 2-3 watts is too much power to
use; a small child can generate only 7-10 watts.  So if we want a decent
"learn" to "generate" ratio, we have to do better than the 2-4 to 1
ratio we might get conventionally.  In January, we saw this staring us
in the face, and knew we had to do better, or we'd have just told a good
fraction of the kids in the world they can't have the advantages of a
computer.  Our goal has always been a 10 to 1 ratio, for at least the
most important use cases (e.g. reading).

(Continue reading)

Jim Gettys | 1 Sep 03:32 2006

[OLPC-devel] Please convert your boards to LinuxBIOS.

Ihe Insyde BIOS has started complaining about the date, and refuse to
boot unless you set the date back.  If you encounter this, just set the
date in the Insyde BIOS in the range of June or July as a temporary
workaround.

But we are now very happy to announce the "Let's stop breaking bones
release!". 

We would like everyone to move to LinuxBIOS, along with:
  o using Linux as a bootloader
  o the gxfb fbdev console device driver
  o the "amd" EXA X Window System driver with early support for 
    alpha blending
  o native Linux support for updating the BIOS flash.
  o JFFS2 file system support for the internal flash
  o Marvell Wireless driver 
        (Please make sure your antennae are installed!)
  o An very early version of the Sugar user interface framework.

Please read the installation directions found at:
http://wiki.laptop.org/go/Upgrading_to_LinuxBIOS carefully, and make
sure you understand them, before starting the upgrade.

On behalf of the many people who made this possible, our great thanks!
                              - Jim Gettys
--

-- 
Jim Gettys
One Laptop Per Child
Zarro Boogs per Child | 1 Sep 04:20 2006

[OLPC-devel] Re: [One Laptop Per Child] #63: Need testers for LB installation

#63: Need testers for LB installation
-------------------------------+--------------------------------------------
 Reporter:  wmb <at> firmworks.com  |        Owner:  jg    
     Type:  task               |       Status:  closed
 Priority:  blocker            |    Milestone:        
Component:  linuxbios          |   Resolution:  fixed 
 Keywords:                     |  
-------------------------------+--------------------------------------------
Changes (by jg):

  * status:  new => closed
  * resolution:  => fixed

--

-- 
Ticket URL: <http://dev.laptop.org/ticket/63#comment:1>
One Laptop Per Child <http://laptop.org/>
Zarro Boogs per Child | 1 Sep 04:21 2006

[OLPC-devel] Re: [One Laptop Per Child] #55: LinuxBIOS won't boot off of ext3 file system not cleanly dismounted.

#55: LinuxBIOS won't boot off of ext3 file system not cleanly dismounted.
-----------------------+----------------------------------------------------
 Reporter:  jg         |        Owner:  marcelo   
     Type:  defect     |       Status:  new       
 Priority:  high       |    Milestone:  rev1 alpha
Component:  linuxbios  |   Resolution:            
 Keywords:             |  
-----------------------+----------------------------------------------------
Changes (by jg):

  * owner:  rminnich => marcelo
  * priority:  blocker => high

--

-- 
Ticket URL: <http://dev.laptop.org/ticket/55#comment:9>
One Laptop Per Child <http://laptop.org/>
Zarro Boogs per Child | 1 Sep 04:23 2006

[OLPC-devel] Re: [One Laptop Per Child] #53: LinuxBIOS sometimes hangs after "Jumping to LinuxBIOS"

#53: LinuxBIOS sometimes hangs after "Jumping to LinuxBIOS"
-------------------------------+--------------------------------------------
 Reporter:  wmb <at> firmworks.com  |        Owner:  rminnich  
     Type:  defect             |       Status:  new       
 Priority:  blocker            |    Milestone:  rev1 alpha
Component:  linuxbios          |   Resolution:            
 Keywords:                     |  
-------------------------------+--------------------------------------------
Changes (by jg):

  * milestone:  => rev1 alpha

Comment:

 We know definitively at least one such hang problem has been fixed.
 However, until we have more data on more systems, we're leaving this open
 to keep ourselves honest.

--

-- 
Ticket URL: <http://dev.laptop.org/ticket/53#comment:17>
One Laptop Per Child <http://laptop.org/>
Zarro Boogs per Child | 1 Sep 04:31 2006

[OLPC-devel] Re: [One Laptop Per Child] #43: Wireless mesh software

#43: Wireless mesh software
-------------------------+--------------------------------------------------
 Reporter:  jg           |        Owner:  marcelo   
     Type:  enhancement  |       Status:  new       
 Priority:  high         |    Milestone:  rev1 alpha
Component:  kernel       |   Resolution:            
 Keywords:               |  
-------------------------+--------------------------------------------------
Changes (by jg):

  * owner:  mbletsas <at> laptop.org => marcelo
  * priority:  blocker => high

Comment:

 The firmware is available from the Marvell web site.

 It is not yet licensed so that we can include it with the base
 distribution, so the bug remains open.

--

-- 
Ticket URL: <http://dev.laptop.org/ticket/43#comment:1>
One Laptop Per Child <http://laptop.org/>

Gmane