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* state[i].transition_latency and state[i].bus_master_latency set to 0. BUG?
@ 2014-08-05 15:37 Ricardo Ribalda Delgado
  2014-09-12  8:55 ` Ricardo Ribalda Delgado
  0 siblings, 1 reply; 2+ messages in thread
From: Ricardo Ribalda Delgado @ 2014-08-05 15:37 UTC (permalink / raw)
  To: linux-acpi, linux-pm, alex@qtec.com

Hello!

I am working with an AMD family 14h Processor. And I believe that the
governor is not behaving as expected.

On the _PSS table, the transition_latency and bus_master_latency are set to 0.

The AMDs BIOS development guide (page 60 and 61)
http://developer.amd.com/wordpress/media/2012/10/43170_14h_Mod_00h-0Fh_BKDG.pdf
they recommend to use value of 0.

Is 0 valid value? The governor will work properly with this value?

What could be a good default value?

Is there a way to experimentally measure the latency?

Thanks for your help!

Extract from dmesg:
[    0.843340] Extracting state 0
[    0.843374] State [0]: core_frequency[1650] power[6075]
transition_latency[0] bus_master_latency[0] control[0x0] status[0x0]
[    0.843481] Extracting state 1
[    0.843513] State [1]: core_frequency[1320] power[3712]
transition_latency[0] bus_master_latency[0] control[0x1] status[0x1]
[    0.843618] Extracting state 2
[    0.843652] State [2]: core_frequency[825] power[1472]
transition_latency[0] bus_master_latency[0] control[0x2] status[0x2]
[    0.843757] Extracting state 3
[    0.843790] State [3]: core_frequency[528] power[1008]
transition_latency[0] bus_master_latency[0] control[0x3] status[0x3]


-- 
Ricardo Ribalda

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: state[i].transition_latency and state[i].bus_master_latency set to 0. BUG?
  2014-08-05 15:37 state[i].transition_latency and state[i].bus_master_latency set to 0. BUG? Ricardo Ribalda Delgado
@ 2014-09-12  8:55 ` Ricardo Ribalda Delgado
  0 siblings, 0 replies; 2+ messages in thread
From: Ricardo Ribalda Delgado @ 2014-09-12  8:55 UTC (permalink / raw)
  To: linux-acpi, linux-pm, alex@qtec.com

Just in case somebody missed this mail in their holiday inbox :)....

Any good ideas for this?

On Tue, Aug 5, 2014 at 5:37 PM, Ricardo Ribalda Delgado
<ricardo.ribalda@gmail.com> wrote:
> Hello!
>
> I am working with an AMD family 14h Processor. And I believe that the
> governor is not behaving as expected.
>
> On the _PSS table, the transition_latency and bus_master_latency are set to 0.
>
> The AMDs BIOS development guide (page 60 and 61)
> http://developer.amd.com/wordpress/media/2012/10/43170_14h_Mod_00h-0Fh_BKDG.pdf
> they recommend to use value of 0.
>
> Is 0 valid value? The governor will work properly with this value?
>
> What could be a good default value?
>
> Is there a way to experimentally measure the latency?
>
> Thanks for your help!
>
> Extract from dmesg:
> [    0.843340] Extracting state 0
> [    0.843374] State [0]: core_frequency[1650] power[6075]
> transition_latency[0] bus_master_latency[0] control[0x0] status[0x0]
> [    0.843481] Extracting state 1
> [    0.843513] State [1]: core_frequency[1320] power[3712]
> transition_latency[0] bus_master_latency[0] control[0x1] status[0x1]
> [    0.843618] Extracting state 2
> [    0.843652] State [2]: core_frequency[825] power[1472]
> transition_latency[0] bus_master_latency[0] control[0x2] status[0x2]
> [    0.843757] Extracting state 3
> [    0.843790] State [3]: core_frequency[528] power[1008]
> transition_latency[0] bus_master_latency[0] control[0x3] status[0x3]
>
>
> --
> Ricardo Ribalda



-- 
Ricardo Ribalda

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2014-08-05 15:37 state[i].transition_latency and state[i].bus_master_latency set to 0. BUG? Ricardo Ribalda Delgado
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