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

From: Qingpeng Yang

Date: Tue Sep 22 2026 - 05:17:53 EST


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@xxxxxxxxxxxxxx> wrote:

On Mon, Sep 14, 2026 at 10:56 AM Xianwei Zhao via B4 Relay
<devnull+xianwei.zhao.amlogic.com@xxxxxxxxxx> wrote:

From: Qingpeng Yang <qingpeng.yang@xxxxxxxxxxx>

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