Re: [PATCH net] net: phylink: print correct c45 phy id when missing PHY driver
From: Andrew Lunn
Date: Sat Jun 20 2026 - 15:25:13 EST
On Sat, Jun 20, 2026 at 03:11:13PM +0200, Aleksander Jan Bajkowski wrote:
> If no PHY driver is found, `phy_id` is returned. `phy_id` holds the c22 ID.
> Modules with a rollball bridge support only c45 transfers. The c45 IDs are
> stored in the `c45_ids` structure. In the current code these modules report
> an ID 0x00000000. This may lead users to mistakenly conclude that the
> rollball bridge isn't properly implemented in their SFP module. This patch
> fixes the wrong IDs for c45 modules when a driver cannot be found.
The problem with C45 is there is not one ID, but multiple IDs. And
they can be from different vendors, depending on who the different IP
blocks have been licensed from.
We came to the conclusion not to report any C45 IDs is the most
meaningful thing to do.
Andrew