Re: [PATCH net-next v2 1/2] net: dsa: mv88e6xxx: use the hw tx queues

[Andrew Lunn <andrew@lunn.ch>]

On Tue, May 26, 2026 at 01:41:14PM +0200, Cedric Jehasse via B4 Relay wrote:
> From: Cedric Jehasse <cedric.jehasse@luminex.be>
> 
> >From the datasheets i've looked at these switches have 4 or 8 transmit
> queues per port.
> There's a PRI field in the dsa tag used to indicate which egress queue
> the frame is to be sent to.
> This isn't done for vlan tagged frames because this would overwrite the
> PCP value in the vlan tag (The PRI field in the dsa
> tag is used as the PCP value in the vlan tag).

Maybe a bit more context would be good here. This patch is about
frames the host is sending to the switch. Looking at just the commit
message this was not obvious. It was only when i looked at the tagger
change did i understand that.

Does DSA_CMD_FORWARD vs DSA_CMD_FROM_CPU make a difference here? Does
DSA_CMD_FROM_CPU skip some classification stages in the switch, where
as DSA_CMD_FORWARD might pass through more stages in the switch and
have the queue over written by the hardware?

	Andrew