Re: [PATCH net] net: usb: asix: ax88772: re-add usbnet_link_change() in phylink callbacks

[Oleksij Rempel <o.rempel@pengutronix.de>]

Hi Markus,

On Fri, May 01, 2026 at 06:39:41PM +0200, Markus Baier wrote:
> Commit e0bffe3e6894 ("net: asix: ax88772: migrate to phylink") replaced
> the asix_adjust_link() PHY callback with phylink's mac_link_up() and
> mac_link_down() handlers, but did not carry over the usbnet_link_change()
> notification that commit 805206e66fab ("net: asix: fix "can't send until
> first packet is send" issue") had added.
> 
> As a result, the original symptom returns: when the link comes up,
> usbnet is never notified, so the RX URB submission stays dormant until
> some other event (e.g. a transmitted packet triggering the status
> endpoint interrupt) wakes it up.
> 
> This is reproducible with the Apple A1277 USB Ethernet Adapter
> (05ac:1402, AX88772A based) on a Banana Pro using a static IPv4
> configuration. After bringing the interface up, no incoming packets are
> received until the first outgoing frame triggers usbnet's RX path.
> 
> Restore the link change notification, gated on a carrier transition so
> the call remains idempotent if the status endpoint also reports the
> change later.
> 
> Fixes: e0bffe3e6894 ("net: asix: ax88772: migrate to phylink")
> Assisted-by: Claude:claude-opus-4-7
> Signed-off-by: Markus Baier <Markus.Baier@soslab.tu-darmstadt.de>

I did some limited testing on AX88772C. Seems to work without
regressions:
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>

Sashiko suggests to update commit message:
https://sashiko.dev/#/patchset/20260501163941.107668-1-Markus.Baier%40soslab.tu-darmstadt.de

Thank you!

Best Regards,
Oleksij
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