e753b63936
[ Upstream commit ac746c8520d9d056b6963ecca8ff1da9929d02f1 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.