Issues with smsc95xx driver since a049a30fc27c

From: Martyn Welch <martyn.welch@collabora.com>
To: netdev@vger.kernel.org
Cc: Krzysztof Kozlowski <krzk@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Gabriel Hojda <ghojda@yo2urs.ro>,
	Markus Reichl <m.reichl@fivetechno.de>,
	Steve Glendinning <steve.glendinning@shawell.net>,
	UNGLinuxDriver@microchip.com,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	stable@kernel.org
Subject: Issues with smsc95xx driver since a049a30fc27c
Date: Fri, 17 Dec 2021 15:45:08 +0000	[thread overview]
Message-ID: <199eebbd6b97f52b9119c9fa4fd8504f8a34de18.camel@collabora.com> (raw)

I've had some reports of the smsc95xx driver failing to work for the
ODROID-X2 and ODROID-U3 since a049a30fc27c was merged (also backported
to 5.15.y stable branch, which I believe is what those affected by this
are using).

Since then we have performed a number of tests, here's what we've found
so far:

ODROID-U3 (built-in LAN9730):

 - No errors reported from smsc95xx driver, however networking broken
   (can not perform DHCP via NetworkManager, Fedora user space).

 - Networking starts working if device forced into promiscuous mode
   (Gabriel noticed this whilst running tcpdump)

ODROID-X2 (built in LAN9514):

 - Networking not brought up (Using Debian Buster and Bullseye with
traditional `/etc/network/interfaces` approach).

 - As with Odroid-u3, works when running in promiscuous mode.

OrangePi Zero with LAN9500A EVK:

 - Network works fine. Interface can be taken up and down, cable
   unplugged and replugged, network continues to work (Debian based
   user space).

Raspberry Pi 1 rev 2 (built-in LAN9512):

 - Network works fine. (Raspberry OS user space)

Raspberry Pi 2 (built-in LAN9514):

 - Booting with DHCP performed by kernel, appears to be working:

    https://lava.collabora.co.uk/scheduler/job/5240174

 - Tested in LAVA (traditional `/etc/network/interfaces` approach),
   networking appears to be working:

    https://lava.collabora.co.uk/scheduler/job/5247952

 - It has been noted that U-Boot uses this device during boot, which
   may be having an impact, however the driver appears to be resetting
   the chip at device bind. Have not been able to replicate this on the
   ODROID-X2 (U-boot environment there doesn't have the network
   driver). This is interesting as the Raspberry Pi 2 and ODROID-X2
   appear to have the same device, yet ones working and the other
   isn't.

Not sure how to approach this now, I've yet to find a device I have
access to that is impacted by this issue.

Martyn