[0/2] net: dsa: lantiq_gswip: two fixes for -net/-stable

Message

Martin Blumenstingl Jan. 3, 2021, 1:25 a.m. UTC

While testing the lantiq_gswip driver in OpenWrt at least one board had
a non-working Ethernet port connected to an internal 100Mbit/s PHY22F
GPHY. The problem which could be observed:
- the PHY would detect the link just fine
- ethtool stats would see the TX counter rise
- the RX counter in ethtool was stuck at zero

It turns out that two independent patches are needed to fix this:
- first we need to enable the MII data lines also for internal PHYs
- second we need to program the GSWIP_MII_CFG registers for all ports
  except the CPU port

These two patches have also been tested by back-porting them on top of
Linux 5.4.86 in OpenWrt.

Special thanks to Hauke for debugging and brainstorming this on IRC
with me!


Martin Blumenstingl (2):
  net: dsa: lantiq_gswip: Enable GSWIP_MII_CFG_EN also for internal PHYs
  net: dsa: lantiq_gswip: Fix GSWIP_MII_CFG(p) register access

 drivers/net/dsa/lantiq_gswip.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)