On 03.04.2024 15:40, Andrew Lunn wrote:
> On Wed, Apr 03, 2024 at 03:18:44PM +0200, Wojciech Drewek wrote:
>>
>>
>> On 02.04.2024 16:46, Andrew Lunn wrote:
>>> On Tue, Apr 02, 2024 at 01:38:59PM +0200, Wojciech Drewek wrote:
>>>>
>>>>
>>>> On 30.03.2024 22:57, Andrew Lunn wrote:
>>>>> On Fri, Mar 29, 2024 at 10:23:18AM +0100, Wojciech Drewek wrote:
>>>>>> Some ethernet modules use nonstandard power levels [1]. Extend ethtool
>>>>>> module implementation to support new attributes that will allow user
>>>>>> to change maximum power. Rename structures and functions to be more
>>>>>> generic. Introduce an example of the new API in ice driver.
>>>>>>
>>>>>> Ethtool examples:
>>>>>> $ ethtool --show-module enp1s0f0np0
>>>>>> Module parameters for enp1s0f0np0:
>>>>>> power-min-allowed: 1000 mW
>>>>>> power-max-allowed: 3000 mW
>>>>>> power-max-set: 1500 mW
>>>>>>
>>>>>> $ ethtool --set-module enp1s0f0np0 power-max-set 4000
>>>>>
>>>>> We have had a device tree property for a long time:
>>>>>
>>>>> maximum-power-milliwatt:
>>>>> minimum: 1000
>>>>> default: 1000
>>>>> description:
>>>>> Maximum module power consumption Specifies the maximum power
>>>>> consumption
>>>>> allowable by a module in the slot, in milli-Watts. Presently,
>>>>> modules can
>>>>> be up to 1W, 1.5W or 2W.
>>>>>
>>>>> Could you flip the name around to be consistent with DT?
>>>>
>>>> Yea, I'm open to any name suggestion although I don't like the unit in the
>>>> parameter name :)
>>>
>>> That is a DT thing. Helps make the units of an ABI obvious. However,
>>> milliwatts is pretty standard with the kernel of user APIs, e.g. all
>>> hwmon calls use milliwatts.
>>>
>>>>>> minimum-power-allowed: 1000 mW
>>>>>> maximum-power-allowed: 3000 mW
>>>>>> maximum-power-set: 1500 mW
>>>>>
>>>>> Also, what does minimum-power-allowed actually tell us? Do you imagine
>>>>> it will ever be below 1W because of bad board design? Do you have a
>>>>> bad board design which does not allow 1W?
>>>>
>>>> Yes. in case of QSFP we don't support 1W, 1.5W is the minimum.
>>>
>>> So if i plug in a 1W QSFP device, it will let the magic smoke out
>>> because it is force fed 1.5W?
>>>
>>> Looking at
>>> https://www.optcore.net/wp-content/uploads/2017/04/QSFP-MSA.pdf table
>>> 7 it indicates different power budget classifications. Power level 1
>>> is a Maximum power of 1.5W. So does your parameter represent this? It
>>> is the minimum maximum power? And your other parameter is the maximum
>>> maximum power?
>>
>> Exactly as you described, minimum-power-allowed is in fact minimum value
>> which maximum-power-set can be set to (so minimum maximum). the other
>> parameter is maximim maximum.
>
> Table 7 in that document is titled "Power Budget Classification". So
> how about
>
> minimum-power-class-allowed: 1000 mW
> maximum-power-class-allowed: 3000 mW
Sounds good
>
> Andrew
