Subject: Re: [PATCH net] net: phy: skip LED triggers on PHYs on SFP modules

From: Daniel Golle <[email-masked]>
Date: Fri, 15 Dec 2023 02:54:20 +0000

On Thu, Dec 14, 2023 at 06:31:23PM -0800, Jakub Kicinski wrote:
> On Tue, 12 Dec 2023 00:05:35 +0000 Daniel Golle wrote:
> > Calling led_trigger_register() when attaching a PHY located on an SFP
> > module potentially (and practically) leads into a deadlock.
> > Fix this by not calling led_trigger_register() for PHYs localted on SFP
> > modules as such modules actually never got any LEDs.
> 
> Any suggestion of a Fixes tag?
> Looks like the triggers were added a while back, are we only seeing it
> now because we started exercising the code more?

I've noticed this as a consequence of commit 2f3ce7a56
"net: sfp: rework the RollBall PHY waiting code"
because (?) some PHYs on SFP+ now probe immediately as the previously
enforced minimum delay now became a timeout.

Blaming that commit would be wrong though, it's more that the problem
has probably always been there and was just previously augmented by
the delay.