This is not fixing any actual bug that I know of, but having a DSA interface that is up even when its lower (master) interface is down is one of those things that just do not sound right. Yes, DSA checks if the master is up before actually bringing the user interface up, but nobody prevents bringing the master interface down immediately afterwards... Then the user ports would attempt dev_queue_xmit on an interface that is down, and wonder what's wrong. This patch prevents that from happening. NETDEV_GOING_DOWN is the notification emitted _before_ the master actually goes down, and we are protected by the rtnl_mutex, so all is well. For those of you reading this because you were doing switch testing such as latency measurements for autonomously forwarded traffic, and you needed a controlled environment with no extra packets sent by the network stack, this patch breaks that, because now the user ports go down too, which may shut down the PHY etc. But please don't do it like that, just do instead: tc qdisc add dev eno2 clsact tc filter add dev eno2 egress flower action drop Tested with two cascaded DSA switches: $ ip link set eno2 down sja1105 spi2.0 sw0p2: Link is Down mscc_felix 0000:00:00.5 swp0: Link is Down fsl_enetc 0000:00:00.2 eno2: Link is Down Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
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.