On Wed, Aug 26, 2026 at 04:04:57PM +0200, Maxime Chevallier wrote:
On dwmac, one of the Unicast filter entries is used to store the local
HW addr. This means that we have to use promisc mode for any kind of
unicast filtering if we only have one slot in our unicast filter.
The number of slots available depends on how the IP is integrated, and
we can't autodiscover how many of these slots we have available, so
the DT property snps,perfect-filter-entries can be used to specify how
many are available.
Most IP variants default to 1 if this isn't specified, which is the case
for the amlogic variants (in this case, S905X3).
Do you have this hardware? Did you try increasing the DT property to
find out how many slots it actually has?
Maybe a nice little project for a newbie which has some stmmac
hardware. Write some code which adds MAC addresses and reads them back
again. Determine at runtime how many slots there actually are.
Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Andrew