Go to file
Oleksij Rempel 2fb7357d50 net: ag71xx: add flow control support
Add flow control support. The functionality was tested on AR9331 SoC and
confirmed by iperf3 results and HW counters exported over ethtool.
Following test configurations was used:

iMX6S receiver <--- TL-SG1005D switch <---- AR9331 sender

The switch is supporting symmytric flow control:
Settings for eth0:
        Supported ports: [ MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Supported pause frame use: Symmetric Receive-only
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Advertised pause frame use: Symmetric
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
--->>   Link partner advertised pause frame use: Symmetric
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 100Mb/s
        Duplex: Full
        Auto-negotiation: on
        Port: MII
        PHYAD: 4
        Transceiver: external
        Link detected: yes

The iMX6S system was configured to 10Mbit, to let the switch use flow
control:
  - ethtool -s eth0 speed 10

With flow control disabled on AR9331:
  - ethtool -A eth0  rx off tx off
  - iperf3 -u -c 172.17.0.1 -b100M -l1472 -t10

[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-10.00  sec  66.2 MBytes  55.5 Mbits/sec  0.000 ms  0/47155 (0%)  sender
[  5]   0.00-10.04  sec  11.5 MBytes  9.57 Mbits/sec  1.309 ms  38986/47146 (83%)  receiver

With flow control enabled on AR9331:
  - ethtool -A eth0  rx on tx on
  - iperf3 -u -c 172.17.0.1 -b100M -l1472 -t10

[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-10.00  sec  15.1 MBytes  12.6 Mbits/sec  0.000 ms  0/10727 (0%)  sender
[  5]   0.00-10.05  sec  11.5 MBytes  9.57 Mbits/sec  1.371 ms  2525/10689 (24%)  receiver

Similar results are get in opposite direction by introducing extra CPU
load on AR9331:
  - chrt 40 dd if=/dev/zero of=/dev/null &

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-11 14:45:54 -07:00
arch arm64: dts: exynos: Use newer S3FWRN5 GPIO properties in Exynos5433 TM2 2020-09-10 15:22:16 -07:00
block block-5.9-2020-09-04 2020-09-04 13:04:51 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-30 15:53:44 -07:00
Documentation wireless-drivers-next patches for v5.10 2020-09-11 13:32:31 -07:00
drivers net: ag71xx: add flow control support 2020-09-11 14:45:54 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
include tcp: reflect tos value received in SYN to the socket 2020-09-10 13:15:40 -07:00
init Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
ipc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
net net/smc: use separate work queues for different worker types 2020-09-10 15:24:27 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-04 21:28:59 -07:00
sound sound fixes for 5.9-rc4 2020-09-04 12:05:25 -07:00
tools selftests/mptcp: Better delay & reordering configuration 2020-09-10 13:28:20 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt * PAE and PKU bugfixes for x86 2020-08-22 10:03:05 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: Add ZSTD-compressed files 2020-07-31 11:50:49 +02:00
.mailmap Merge branch 'akpm' (patches from Andrew) 2020-08-21 14:44:48 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Add Krzysztof Kozlowski to Samsung S3FWRN5 and remove Robert 2020-09-10 15:22:16 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Add Krzysztof Kozlowski to Samsung S3FWRN5 and remove Robert 2020-09-10 15:22:16 -07:00
Makefile Linux 5.9-rc3 2020-08-30 16:01:54 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.