[PATCH] pmdomain: amlogic: Keep Amlogic A9 ETH domain always on

[Qingpeng Yang]

Hi Uffe,
     Thanks for your review.

On 9/15/2026 11:47 PM, Ulf Hansson wrote:
> 
> On Mon, Sep 14, 2026 at 12:40 PM Martin Blumenstingl
> <martin.blumenstingl at googlemail.com> wrote:
>>
>> On Mon, Sep 14, 2026 at 10:56 AM Xianwei Zhao via B4 Relay
>> <devnull+xianwei.zhao.amlogic.com at kernel.org> wrote:
>>>
>>> From: Qingpeng Yang <qingpeng.yang at amlogic.com>
>>>
>>> Mark the A9 ethernet power domain as always-on since it is required
>>> for ethernet online wakeup and must not be powered down.
>> Is "online wakeup" a wake up from suspend?
>> If so: is the Ethernet controller listed with the "wakeup-source" flag
>> in .dts{,i}?
>> I'm wondering if the pmdomain and/or power (wakeup) frameworks in
>> Linux have other ways of managing this case (e.g. only keeping the
>> power domain active if needed).
> 
> We certainly do.
> 
> For in-band wakeup we have GENPD_FLAG_ACTIVE_WAKEUP. If this is set
> for the genpd in question and the device being suspended is configured
> for system wakeup (device_awake_path() returns true), the genpd will
> remain powered on during system suspend, see genpd_finish_suspend().
> 
> In genpd_finish_suspend() we also support out-band wakeups via
> checking device_out_band_wakeup(). Although, I guess that's not the
> case here.

Thanks for pointing out GENPD_FLAG_ACTIVE_WAKEUP and the
genpd_finish_suspend() logic. That is very helpful.

When we do need Ethernet wakeup support later, we will revisit this and
follow the approach you described, including the proper use of
GENPD_FLAG_ACTIVE_WAKEUP and the wakeup-source configuration.

> 
> Kind regards
> Uffe