Re: [PATCH net v2 0/2] Fix PHY handle no longer parsing

[Russell King (Oracle)]

On Tue, Mar 21, 2023 at 08:37:48AM +0000, Sit, Michael Wei Hong wrote:
> 
> 
> > -----Original Message-----
> > From: Russell King <linux@xxxxxxxxxxxxxxx>
> > Sent: Saturday, March 18, 2023 4:54 AM
> > To: Sit, Michael Wei Hong <michael.wei.hong.sit@xxxxxxxxx>
> > Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>; Alexandre
> > Torgue <alexandre.torgue@xxxxxxxxxxx>; Jose Abreu
> > <joabreu@xxxxxxxxxxxx>; David S . Miller
> > <davem@xxxxxxxxxxxxx>; Eric Dumazet
> > <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>;
> > Paolo Abeni <pabeni@xxxxxxxxxx>; Maxime Coquelin
> > <mcoquelin.stm32@xxxxxxxxx>; Ong, Boon Leong
> > <boon.leong.ong@xxxxxxxxx>; netdev@xxxxxxxxxxxxxxx; linux-
> > stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx; linux-arm-
> > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Looi,
> > Hong Aun <hong.aun.looi@xxxxxxxxx>; Voon, Weifeng
> > <weifeng.voon@xxxxxxxxx>; Lai, Peter Jun Ann
> > <peter.jun.ann.lai@xxxxxxxxx>
> > Subject: Re: [PATCH net v2 0/2] Fix PHY handle no longer parsing
> > 
> > On Tue, Mar 14, 2023 at 03:02:06PM +0800, Michael Sit Wei Hong
> > wrote:
> > > After the fixed link support was introduced, it is observed that
> > PHY
> > > no longer attach to the MAC properly.
> > 
> > You are aware, I hope, that fixed-link and having a PHY are
> > mutually exclusive?
> > 
> > In other words, you can't use fixed-link to specify parameters for
> > a PHY.
> > 
> Yes but when the fixed-link support code was added, all our non
> fixed-link devices are not attaching the PHYs to the MACs, hence
> the reason for this patch series, to ensure both fixed-link and
> non fixed-link scenarios work properly.

Ah, it's the "there should be a PHY here" case you're trying to cater
for, rather than actually a fixed-link.

So, how about adding a helper that is basically:

bool phylink_expects_phy(struct phylink *phylink)
{
	return pl->cfg_link_an_mode == MLO_AN_PHY;
}
EXPORT_SYMBOL_GPL(phylink_expects_phy);

and use that to test whether you need to manually find a PHY to attach,
rather than trying to detect whether a fixed-link stanza appears in
firmware?

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!