[Intel-wired-lan] [PATCH v1 3/3] e1000e: Additional PHY power saving in s0ix

[Sasha Neftin]

On 7/14/2021 09:09, Paul Menzel wrote:
> Dear Sasha,
> 
> 
> Am 13.07.21 um 18:40 schrieb Sasha Neftin:
>> On 7/13/2021 10:12, Paul Menzel wrote:
> 
>>> Am 24.06.21 um 10:19 schrieb Sasha Neftin:
>>>
>>> Could you please use a statement in the commit message summary? Maybe:
>>>
>>>> Disable additional PHY features(?) in S0ix
>>>
>>>> After transferring the MAC-PHY interface to the SMBus the PHY
>>>> will save power in S0ix low power idle mode.
>>>
>>> I do not understand this. Please rewrite, and mention the three PHY 
>>> features(?) you change.
>>>
>>> Please document how you tested this, and exactly how much power is 
>>> saved.
> 
>> The PHY will save 47-85mW in s0ix. It is tested (by our electrical 
>> validation team) on a sense resistor on a specific external board over 
>> the TGL platform.
>>
>> This measurement could variate from platform to platform and depends 
>> on the specific platform design.
> 
> Thank you for sharing the data. Please add it to the commit message in v2.
Paul, I will work on this with our HW architect. We will process 
specification updates. I will let you know and share since it will ready.
> 
>>>> Suggested-by: Dima Ruinskiy <dima.ruinskiy at intel.com>
>>>> Signed-off-by: Sasha Neftin <sasha.neftin at intel.com>
>>>> ---
>>>>   drivers/net/ethernet/intel/e1000e/netdev.c | 6 ++++++
>>>>   1 file changed, 6 insertions(+)
>>>>
>>>> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c 
>>>> b/drivers/net/ethernet/intel/e1000e/netdev.c
>>>> index 6e6e2e685e9d..c4f3e5ca7294 100644
>>>> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
>>>> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
>>>> @@ -6380,10 +6380,16 @@ static void e1000e_s0ix_entry_flow(struct 
>>>> e1000_adapter *adapter)
>>>>           ew32(CTRL_EXT, mac_data);
>>>>             /* DFT control: PHY bit: page769_20[0] = 1
>>>> +         * page769_20[7] - PHY PLL stop
>>>> +         * page769_20[8] - PHY go to the electrical idle
>>>> +         * page769_20[9] - PHY serdes disable
>>>>            * Gate PPW via EXTCNF_CTRL - set 0x0F00[7] = 1
>>>>            */
>>>>           e1e_rphy(hw, I82579_DFT_CTRL, &phy_data);
>>>>           phy_data |= BIT(0);
>>>> +        phy_data |= BIT(7);
>>>> +        phy_data |= BIT(8);
>>>> +        phy_data |= BIT(9);
>>>>           e1e_wphy(hw, I82579_DFT_CTRL, phy_data);
>>>>             mac_data = er32(EXTCNF_CTRL);
>>>>
> 
> 
> Kind regards,
> 
> Paul
Sasha