Re: [PATCH net-next v2 0/5] TSN auto negotiation between 1G and 2.5G

Andrew Lunn
2023-09-21T21:11:19Z

On Thu, Sep 21, 2023 at 03:12:19PM +0100, Russell King (Oracle) wrote:
> On Thu, Sep 21, 2023 at 03:21:00PM +0200, Andrew Lunn wrote:
> > > Hi Andrew,
> > >
> > > After conducting a comprehensive study, it seems that implementing
> > > out-of-band for all link modes might not be feasible. I may have missed some
> > > key aspects during my analysis.
> > >
> > > Would you be open to sharing a high-level idea of how we could potentially
> > > make this feasible? Your insights would be greatly appreciated.
> >
> > stmmac_mac_link_up() gets passed interface, speed and duplex. That
> > tells you what the PHY has negotiated. Is there anything else you need
> > to know?
>
> The problem is... the stmmac driver is utter bollocks - that information
> is *not* passed to the BSP. Instead, stmmac parse and store information
> such as the PHY interface mode at initialisation time. BSPs also re-
> parse and store e.g. the PHY interface mode at initialisation time.
> The driver ignores what it gets from phylink.
>
> The driver is basically utter crap. That's an area I _had_ patches to
> clean up. I no longer do. stmmac is crap crap crap and will stay crap
> until they become more receptive to patches to fix it, even if the
> patches are not 100% to their liking but are in fact correct. Maybe
> if I ever decide to touch that driver in the future. Which I doubt
> given my recent experience.

Hi Russell

You pointed out the current proposal will break stuff. Do you see a
way forward for this patchset which does not first involve actually
cleaning up of this driver?

Andrew