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Frank Li 538d850485 usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM
[ Upstream commit dbe678f619 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2023-06-09 10:32:31 +02:00
arch powerpc/iommu: Limit number of TCEs to 512 for H_STUFF_TCE hcall 2023-06-09 10:32:31 +02:00
block block/blk-iocost (gcc13): keep large values in a new enum 2023-06-09 10:32:30 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: engine - fix crypto_queue backlog handling 2023-05-17 11:50:20 +02:00
Documentation dt-bindings: usb: snps,dwc3: Fix "snps,hsphy_interface" type 2023-06-09 10:32:29 +02:00
drivers usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM 2023-06-09 10:32:31 +02:00
fs btrfs: fix csum_tree_block page iteration to avoid tripping on -Werror=array-bounds 2023-06-09 10:32:31 +02:00
include media: dvb-core: Fix use-after-free due to race at dvb_register_device() 2023-06-09 10:32:24 +02:00
init kbuild: Add CONFIG_PAHOLE_VERSION 2023-02-25 12:06:45 +01:00
io_uring io_uring: avoid null-ptr-deref in io_arm_poll_handler 2023-03-22 13:31:37 +01:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:28:45 +01:00
kernel bpf: fix a memory leak in the LRU and LRU_PERCPU hash maps 2023-06-05 09:21:14 +02:00
lib debugobjects: Don't wake up kswapd from fill_pool() 2023-05-30 13:55:31 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs 2023-05-11 23:00:18 +09:00
net atm: hide unused procfs functions 2023-06-09 10:32:26 +02:00
samples samples/bpf: Fix fout leak in hbm's run_bpf_prog 2023-05-24 17:36:45 +01:00
scripts recordmcount: Fix memory leaks in the uwrite function 2023-05-24 17:36:47 +01:00
security selinux: ensure av_permissions.h is built when needed 2023-05-11 23:00:19 +09:00
sound ALSA: oss: avoid missing-prototype warnings 2023-06-09 10:32:26 +02:00
tools Bonding: add arp_missed_max option 2023-06-05 09:21:19 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: fix memoryleak in kvm_init() 2023-03-17 08:49:04 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +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: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
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 platform/x86: Move existing HP drivers to a new hp subdir 2023-05-24 17:36:48 +01:00
Makefile Linux 5.15.115 2023-06-05 09:21:27 +02:00
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.