net: stmmac: enhance XDP ZC driver level switching performance
The previous stmmac_xdp_set_prog() implementation uses stmmac_release()
and stmmac_open() which tear down the PHY device and causes undesirable
autonegotiation which causes a delay whenever AFXDP ZC is setup.
This patch introduces two new functions that just sufficiently tear
down DMA descriptors, buffer, NAPI process, and IRQs and reestablish
them accordingly in both stmmac_xdp_release() and stammac_xdp_open().
As the results of this enhancement, we get rid of transient state
introduced by the link auto-negotiation:
$ ./xdpsock -i eth0 -t -z
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 634444 634560
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 632330 1267072
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 632438 1899584
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 632502 2532160
Reported-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>