Re: [PATCH] net: ethernet: ti: cpsw_ale: optimize cpsw_ale_restore()

From: Jakub Kicinski
Date: Thu Nov 10 2022 - 15:33:08 EST


On Thu, 10 Nov 2022 11:39:47 +0200 Roger Quadros wrote:
> > Maybe my tree is old but I see we clear only if there is a netdev that
>
> This patch depends on this series
> https://lore.kernel.org/netdev/20221104132310.31577-3-rogerq@xxxxxxxxxx/T/

I do have those in my tree.

> > needs to be opened but then always call ale_restore(). Is that okay?
>
> If netdev is closed and opened ale_restore() is not called.
> ale_restore() is only called during system suspend/resume path
> since CPSW-ALE might have lost context during suspend and we want to restore
> all valid ALE entries.

Ack, what I'm referring to is the contents of am65_cpsw_nuss_resume().

I'm guessing that ALE_CLEAR is expected to be triggered by
cpsw_ale_start().

Assuming above is true and that ALE_CLEAR comes from cpsw_ale_start(),
the call stack is:

cpsw_ale_start()
am65_cpsw_nuss_common_open()
am65_cpsw_nuss_ndo_slave_open()
am65_cpsw_nuss_resume()

but resume() only calls ndo_slave_open under certain conditions:

for (i = 0; i < common->port_num; i++) {
if (netif_running(ndev)) {
rtnl_lock();
ret = am65_cpsw_nuss_ndo_slave_open(ndev);

Is there another path? Or perhaps there's nothing to restore
if all netdevs are down?

> I have a question here. How should ageable entries be treated in this case?

Ah, no idea :) Let's me add experts to To: