A mirror of the official Linux kernel repository just in case
Go to file
Frank Li dbe678f619 usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM
At iMX8QM platform, enable NCM gadget and run 'iperf3 -s'.
At host, run 'iperf3 -V -c fe80::6863:98ff:feef:3e0%enxc6e147509498'

[  5]   0.00-1.00   sec  1.55 MBytes  13.0 Mbits/sec   90   4.18 KBytes
[  5]   1.00-2.00   sec  1.44 MBytes  12.0 Mbits/sec   75   4.18 KBytes
[  5]   2.00-3.00   sec  1.48 MBytes  12.4 Mbits/sec   75   4.18 KBytes

Expected speed should be bigger than 300Mbits/sec.

The root cause of this performance drop was found to be data corruption
happening at 4K borders in some Ethernet packets, leading to TCP
checksum errors. This corruption occurs from the position
(4K - (address & 0x7F)) to 4K. The u_ether function's allocation of
skb_buff reserves 64B, meaning all RX addresses resemble 0xXXXX0040.

Force trb_burst_size to 16 can fix this problem.

Cc: stable@vger.kernel.org
Fixes: 7733f6c32e ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20230518154946.3666662-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-29 15:23:59 +01:00
arch A single fix for x86: 2023-05-28 07:42:05 -04:00
block block: make bio_check_eod work for zero sized devices 2023-05-24 08:19:26 -06:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto This push fixes the following problems: 2023-05-07 10:57:14 -07:00
Documentation A set of fixes for interrupt chip drivers: 2023-05-28 07:12:21 -04:00
drivers usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM 2023-05-29 15:23:59 +01:00
fs for-6.4-rc3-tag 2023-05-26 13:21:38 -07:00
include A set of unwinder and tooling fixes: 2023-05-28 07:33:29 -04:00
init Objtool changes for v6.4: 2023-04-28 14:02:54 -07:00
io_uring io_uring: unlock sqd->lock before sq thread release CPU 2023-05-25 09:30:13 -06:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Two fixes for debugobjects: 2023-05-28 07:15:33 -04:00
lib Two fixes for debugobjects: 2023-05-28 07:15:33 -04:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: fix zswap writeback race condition 2023-05-17 15:24:33 -07:00
net Networking fixes for 6.4-rc4, including fixes from bluetooth and bpf 2023-05-25 10:55:26 -07:00
rust Rust changes for v6.4 2023-04-30 11:20:22 -07:00
samples samples/bpf: Drop unnecessary fallthrough 2023-05-16 19:44:05 +02:00
scripts Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
security integrity-v6.4 2023-04-29 10:11:32 -07:00
sound ALSA: hda/realtek: Enable headset onLenovo M70/M90 2023-05-24 14:18:59 +02:00
tools cxl fixes for v6.4-rc4 2023-05-26 17:45:24 -07:00
usr initramfs: Check negative timestamp to prevent broken cpio archive 2023-04-16 17:37:01 +09:00
virt KVM: Fix vcpu_array[0] races 2023-05-19 13:56:26 -04:00
.clang-format cxl for v6.4 2023-04-30 11:51:51 -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 *.dtso files 2023-02-26 15:28:23 +09:00
.gitignore linux-kselftest-kunit-6.4-rc1 2023-04-24 12:31:32 -07:00
.mailmap mailmap: add entries for Nikolay Aleksandrov 2023-05-17 09:35:05 +01:00
.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: sctp: move Neil to CREDITS 2023-05-12 08:51:32 +01:00
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 ARM: SoC fixes for 6.4 2023-05-26 16:17:56 -07:00
Makefile Linux 6.4-rc4 2023-05-28 07:49:00 -04:00
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 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.