Re: [net-next,PATCH] net: stmmac: stm32: Do not suspend downed interface

Russell King (Oracle)
2026-01-14T16:29:24Z

On Wed, Jan 14, 2026 at 09:17:54AM +0100, Marek Vasut wrote:
> If an interface is down, the ETHnSTP clock are not running. Suspending
> such an interface will attempt to stop already stopped ETHnSTP clock,
> and produce a warning in the kernel log about this.
>
> STM32MP25xx that is booted from NFS root via its first ethernet MAC
> (also the consumer of ck_ker_eth1stp) and with its second ethernet
> MAC downed produces the following warnings during suspend resume
> cycle. This can be provoked even using pm_test:
>
> "
> $ echo devices > /sys/power/pm_test
> $ echo mem > /sys/power/state
> ...
> ck_ker_eth2stp already disabled
> ...
> ck_ker_eth2stp already unprepared
> ...
> "
>
> Fix this by not manipulating with the clock during suspend resume
> of interfaces which are downed.

I don't think this is the correct fix. Looking back at my commits:
b51f34bc85e3 net: stmmac: platform: legacy hooks for suspend()/resume() methods
07bbbfe7addf net: stmmac: add suspend()/resume() platform ops

I think I changed the behaviour of the suspend/resume callbacks
unintentionally. Sorry, I don't have time to complete this email
(meeting.)

--
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