kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-04 19:54:59 +00:00
Code Issues Releases Packages Activity
No description
1,382,875 commits 117 branches 5,815 tags 6.2 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Jacob Keller 503f1c72c3 i40e: fix Jumbo Frame support after iPXE boot 
The i40e hardware has multiple hardware settings which define the Maximum
Frame Size (MFS) of the physical port. The firmware has an AdminQ command
(0x0603) to configure the MFS, but the i40e Linux driver never issues this
command.

In most cases this is no problem, as the NVM default value has the device
configured for its maximum value of 9728. Unfortunately, recent versions of
the iPXE intelxl driver now issue the 0x0603 Set Mac Config command,
modifying the MFS and reducing it from its default value of 9728.

This occurred as part of iPXE commit 6871a7de705b ("[intelxl] Use admin
queue to set port MAC address and maximum frame size"), a prerequisite
change for supporting the E800 series hardware in iPXE. Both the E700 and
E800 firmware support the AdminQ command, and the iPXE code shares much of
the logic between the two device drivers.

The ice E800 Linux driver already issues the 0x0603 Set Mac Config command
early during probe, and is thus unaffected by the iPXE change.

Since commit 3a2c6ced90 ("i40e: Add a check to see if MFS is set"), the
i40e driver does check the I40E_PRTGL_SAH register, but it only logs a
warning message if its value is below the 9728 default. This register also
only covers received packets and not transmitted packets. A warning can
inform system administrators, but does not correct the issue. No
interactions from userspace cause the driver to write to PRTGL_SAH or issue
the 0x0603 AdminQ command. Only a GLOBR reset will restore the value to its
default value. There is no obvious method to trigger a GLOBR reset from
user space.

To fix this, introduce the i40e_aq_set_mac_config() function, similar to
the one from the ice driver. Call this during early probe to ensure that
the device configuration matches driver expectation. Unlike E800, the E700
firmware also has a bit to control whether the MAC should append CRC data.
It is on by default, but setting a 0 to this bit would disable CRC. The
i40e implementation must set this bit to ensure CRC will be appended by the
MAC.

In addition to the AQ command, instead of just checking the I40E_PRTGL_SAH
register, update its value to the 9728 default and write it back. This
ensures that the hardware is in the expected state, regardless of whether
the iPXE (or any other early boot driver) has modified this state.

This is a better user experience, as we now fix the issues with larger MTU
instead of merely warning. It also aligns with the way the ice E800 series
driver works.

A final note: The Fixes tag provided here is not strictly accurate. The
issue occurs as a result of an external entity (the iPXE intelxl driver),
and this is not a regression specifically caused by the mentioned change.
However, I believe the original change to just warn about PRTGL_SAH being
too low was an insufficient fix.

Fixes: 3a2c6ced90 ("i40e: Add a check to see if MFS is set")
Link: 6871a7de70
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Michal Schmidt <mschmidt@redhat.com>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
History 2025-09-09 10:29:53 -07:00
arch Including fixes from netfilter, wireless and Bluetooth. 2025-09-04 09:59:15 -07:00
block block: validate QoS before calling __rq_qos_done_bio() 2025-08-26 10:34:08 -06:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Significant patch series in this pull request: 2025-08-03 16:23:09 -07:00
Documentation Including fixes from netfilter, wireless and Bluetooth. 2025-09-04 09:59:15 -07:00
drivers i40e: fix Jumbo Frame support after iPXE boot 2025-09-09 10:29:53 -07:00
fs a ksmbd server fix 2025-09-03 20:44:15 -07:00
include Including fixes from netfilter, wireless and Bluetooth. 2025-09-04 09:59:15 -07:00
init hardening: Require clang 20.1.0 for __counted_by 2025-08-29 12:04:53 -07:00
io_uring io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths 2025-08-28 05:48:34 -06:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel sched: Fix sched_numa_find_nth_cpu() if mask offline 2025-09-03 12:20:06 -04:00
lib hardening fixes for v6.17-rc4 2025-08-31 08:56:45 -07:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm slab fixes for 6.17-rc5 2025-09-04 09:54:20 -07:00
net tunnels: reset the GSO metadata before reusing the skb 2025-09-09 13:03:33 +02:00
rust rust: mm: mark VmaNew as transparent 2025-08-27 22:45:41 -07:00
samples Significant patch series in this pull request: 2025-08-03 16:23:09 -07:00
scripts kasan: fix GCC mem-intrinsic prefix with sw tags 2025-08-27 22:45:43 -07:00
security + Features 2025-08-04 08:17:28 -07:00
sound ALSA: hda/hdmi: Add pin fix for another HP EliteDesk 800 G4 model 2025-09-01 13:51:57 +02:00
tools selftests: net: add test for destination in broadcast packets 2025-09-09 11:29:58 +02:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge tag 'kvm-x86-no_assignment-6.17' of https://github.com/kvm-x86/linux into HEAD 2025-07-29 08:36:42 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore gitignore: allow .pylintrc to be tracked 2025-07-02 17:10:04 -06:00
.mailmap MAINTAINERS: Update Nobuhiro Iwamatsu's email address 2025-09-01 10:36:10 +02:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.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 MAINTAINERS: retire Boris from TLS maintainers 2025-08-26 17:36:01 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Including fixes from netfilter, wireless and Bluetooth. 2025-09-04 09:59:15 -07:00
Makefile Linux 6.17-rc4 2025-08-31 15:33:07 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.