Go to file
Sergei Antonov 37c8489012 net: ftmac100: allow increasing MTU to make most use of single-segment buffers
If the FTMAC100 is used as a DSA master, then it is expected that frames
which are MTU sized on the wire facing the external switch port (1500
octets in L2 payload, plus L2 header) also get a DSA tag when seen by
the host port.

This extra tag increases the length of the packet as the host port sees
it, and the FTMAC100 is not prepared to handle frames whose length
exceeds 1518 octets (including FCS) at all.

Only a minimal rework is needed to support this configuration. Since
MTU-sized DSA-tagged frames still fit within a single buffer (RX_BUF_SIZE),
we just need to optimize the resource management rather than implement
multi buffer RX.

In ndo_change_mtu(), we toggle the FTMAC100_MACCR_RX_FTL bit to tell the
hardware to drop (or not) frames with an L2 payload length larger than
1500. We need to replicate the MACCR configuration in ftmac100_start_hw()
as well, since there is a hardware reset there which clears previous
settings.

The advantage of dynamically changing FTMAC100_MACCR_RX_FTL is that when
dev->mtu is at the default value of 1500, large frames are automatically
dropped in hardware and we do not spend CPU cycles dropping them.

Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Sergei Antonov <saproj@gmail.com>
Link: https://lore.kernel.org/r/20221028183220.155948-3-saproj@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-31 20:02:57 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-27 16:56:36 -07:00
block block-6.1-2022-10-20 2022-10-21 15:14:14 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
Documentation dt-bindings: net: snps,dwmac: Document queue config subnodes 2022-10-31 09:08:42 +00:00
drivers net: ftmac100: allow increasing MTU to make most use of single-segment buffers 2022-10-31 20:02:57 -07:00
fs execve fixes for v6.1-rc3 2022-10-27 13:16:36 -07:00
include rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link 2022-10-31 18:10:21 -07:00
init init: Kconfig: fix spelling mistake "satify" -> "satisfy" 2022-10-20 21:27:22 -07:00
io_uring io_uring/net: fail zc sendmsg when unsupported by socket 2022-10-22 08:43:03 -06:00
ipc - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-24 13:44:11 -07:00
lib Including fixes from 802.15.4 (Zigbee et al.). 2022-10-27 13:36:59 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/huge_memory: do not clobber swp_entry_t during THP split 2022-10-20 21:27:24 -07:00
net rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link 2022-10-31 18:10:21 -07:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-20 17:49:10 -07:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
sound sound fixes for 6.1-rc1 2022-10-14 13:22:14 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-27 16:56:36 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm: Add support for arch compat vm ioctls 2022-10-22 05:15:23 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap mailmap: update email for Qais Yousef 2022-10-20 21:27:21 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS net: phy: Add driver for Motorcomm yt8521 gigabit ethernet phy 2022-10-31 10:51:54 +00:00
Makefile Linux 6.1-rc2 2022-10-23 15:27:33 -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.