linux-omap pm branch

linux-omap pm branch

[Hunter, Jon]

Hi All,

I want to run some tests using the linux-omap pm branch on the omap3430 and had a couple questions...

1). What omap3430 board(s) are being using to validate the pm branch functionality?

2). Is there a list of pm features are currently supported/functional for omap3430? For example, cpuidle, cpufreq, retention, off-mode, smart-reflex, suspend/restore, etc. 

3). Are there any userspace tools (such as powertop) that are recommended for monitoring power states?

Cheers
Jon

RE: linux-omap pm branch

[Premi, Sanjeev]

> -----Original Message-----
> From: linux-omap-owner@vger.kernel.org 
> [mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Hunter, Jon
> Sent: Tuesday, May 12, 2009 2:45 AM
> To: linux-omap@vger.kernel.org
> Subject: linux-omap pm branch 
> 
> Hi All,
> 
> I want to run some tests using the linux-omap pm branch on 
> the omap3430 and had a couple questions...
> 
> 1). What omap3430 board(s) are being using to validate the pm 
> branch functionality?

[sp] I believe most common are omap3evm and beagle.

> 
> 2). Is there a list of pm features are currently 
> supported/functional for omap3430? For example, cpuidle, 
> cpufreq, retention, off-mode, smart-reflex, suspend/restore, etc. 

[sp] All of above - though all drivers may not support power
     management. Hence you may see some failures scenarios
     esp. with off mode.

> 
> 3). Are there any userspace tools (such as powertop) that are 
> recommended for monitoring power states?

[sp] You can definitely use powertop.

Best regards,
Sanjeev

> 
> Cheers
> Jon
> --
> To unsubscribe from this list: send the line "unsubscribe 
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> 
> 

RE: linux-omap pm branch

[Hunter, Jon]

Hi Sanjeev,

> > 1). What omap3430 board(s) are being using to validate the pm
> > branch functionality?
> 
> [sp] I believe most common are omap3evm and beagle.

Do you know if we are doing any validation on the SDP3430 or Zoom boards? 

Using defconfig for the SDP3430 the kernel failed to boot. I found that this was due to the MUSB driver and SmartReflex. Disabling these allows it to boot.

> > 2). Is there a list of pm features are currently
> > supported/functional for omap3430? For example, cpuidle,
> > cpufreq, retention, off-mode, smart-reflex, suspend/restore, etc.
> 
> [sp] All of above - though all drivers may not support power
>      management. Hence you may see some failures scenarios
>      esp. with off mode.

Off mode does not appear to be working currently on the SDP. It hangs when enabled. Is off-mode stable on any of the boards?

 
> > 3). Are there any userspace tools (such as powertop) that are
> > recommended for monitoring power states?
> 
> [sp] You can definitely use powertop.

Is this what everyone is using or is there any other diagnostics available through the proc or sys file-systems? Powertop is fine but I am curious how people are validating which c-states are being entered. 

Cheers
Jon

RE: linux-omap pm branch

[Nayak, Rajendra]

>-----Original Message-----
>From: linux-omap-owner@vger.kernel.org 
>[mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Hunter, Jon
>Sent: Tuesday, May 12, 2009 4:09 AM
>To: Premi, Sanjeev; linux-omap@vger.kernel.org
>Subject: RE: linux-omap pm branch 
>
>Hi Sanjeev,
>
>> > 1). What omap3430 board(s) are being using to validate the pm
>> > branch functionality?
>> 
>> [sp] I believe most common are omap3evm and beagle.
>
>Do you know if we are doing any validation on the SDP3430 or 
>Zoom boards? 

Jon,

Most of the validation on the 3430SDP have been done using a minimal
defconfig, omap_3430sdp_min_defconfig.

>
>Using defconfig for the SDP3430 the kernel failed to boot. I 
>found that this was due to the MUSB driver and SmartReflex. 
>Disabling these allows it to boot.
>
>> > 2). Is there a list of pm features are currently
>> > supported/functional for omap3430? For example, cpuidle,
>> > cpufreq, retention, off-mode, smart-reflex, suspend/restore, etc.
>> 
>> [sp] All of above - though all drivers may not support power
>>      management. Hence you may see some failures scenarios
>>      esp. with off mode.
>
>Off mode does not appear to be working currently on the SDP. 
>It hangs when enabled. Is off-mode stable on any of the boards?

If you tried with the default config (omap_3430sdp_defconfig) it most probably does hang.
Not all drivers do context save/restore today. Only the ones enabled in the minimal defconfig
do.

>
> 
>> > 3). Are there any userspace tools (such as powertop) that are
>> > recommended for monitoring power states?
>> 
>> [sp] You can definitely use powertop.
>
>Is this what everyone is using or is there any other 
>diagnostics available through the proc or sys file-systems? 
>Powertop is fine but I am curious how people are validating 
>which c-states are being entered. 

There is a few debugfs entries which throw count of how many times
a power/clock domain has been in a given state.
Most of the implementation of these counters is in mach-omap2/pm-debug.c

http://marc.info/?l=linux-omap&m=122399525014763&w=2

regards,
Rajendra

>
>Cheers
>Jon
>--
>To unsubscribe from this list: send the line "unsubscribe 
>linux-omap" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>

Re: linux-omap pm branch

[Kevin Hilman]

Hi Jon,

"Hunter, Jon" <jon-hunter@ti.com> writes:

> I want to run some tests using the linux-omap pm branch on the omap3430 and had a couple questions...
>
> 1). What omap3430 board(s) are being using to validate the pm branch functionality?

I typically validate on Beagle, OMAP3EVM and RX51.  Some folks in TII
have done some validation on SDP as well.

On SDP, I have noted that CORE powerdomain does not hit retention on
current PM branch yet the same code hits full-chip retention and OFF
on the other OMAP3 boards.  I have not yet fully debugged this and I
haven't heard from other TI folks if they have the same problem.

> 2). Is there a list of pm features are currently supported/functional for omap3430? For example, cpuidle, cpufreq, retention, off-mode, smart-reflex, suspend/restore, etc. 

All of the above.

But as others have mentioned, these are validated on a minimal kernel
since there is still driver/subsystem work required to support PM,
especially the context save/restore needed for off mode.

> 3). Are there any userspace tools (such as powertop) that are
> recommended for monitoring power states?

I use powertop when testing CPUidle, but but some of the in-kernel PM
debug features are also useful.  For example, you can see some
powerdomain and clockdomain accounting by enabling CONFIG_PM_DEBUG and
CONFIG_DEBUG_FS, then mounting debugfs and doing:

# cat /debug/pm_debug/count

Also, there's a patch in the PM branch which saves the PRCM registers
just before jumping to SRAM.  This snapshot can be dumped by doing:

# cat /debug/pm_debug/registers/1

This allows you to use the registers to check if there are any clocks
enabled or any clockactivity.

Kevin