kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-08 18:57:22 +00:00
Code Issues Releases Packages Activity
No description
1,189,811 commits 117 branches 5,824 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
Vidya Sagar 44191fb06d Revert "PCI: tegra194: Enable support for 256 Byte payload" 
commit ebfde1584d upstream.

After commit 4fb8e46c1b ("PCI: tegra194: Enable support for 256 Byte
payload"), we initialize MPS=256 for tegra194 Root Ports before enumerating
the hierarchy.

Consider an Endpoint that supports only MPS=128.  In the default situation
(CONFIG_PCIE_BUS_DEFAULT set and no "pci=pcie_bus_*" parameter), Linux
tries to configure the MPS of every device to match the upstream bridge.
If the Endpoint is directly below the Root Port, Linux can reduce the Root
Port MPS to 128 to match the Endpoint.  But if there's a switch in the
middle, Linux doesn't reduce the Root Port MPS because other devices below
the switch may already be configured with MPS larger than 128.

This scenario results in uncorrectable Malformed TLP errors if the Root
Port sends TLPs with payloads larger than 128 bytes.  These errors can
be avoided by using the "pci=pcie_bus_safe" parameter, but it doesn't
seem to be a good idea to always have this parameter even for basic
functionality to work.

Revert commit 4fb8e46c1b ("PCI: tegra194: Enable support for 256 Byte
payload") so the Root Ports default to MPS=128, which all devices
support.

If peer-to-peer DMA is not required, one can use "pci=pcie_bus_perf" to
get the benefit of larger MPS settings.

[bhelgaas: commit log; kwilczynski: retain "u16 val_16" declaration at
the top, add missing acked by tag]
Fixes: 4fb8e46c1b ("PCI: tegra194: Enable support for 256 Byte payload")
Link: https://lore.kernel.org/linux-pci/20230619102604.3735001-1-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Cc: stable@vger.kernel.org # v6.0-rc1+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2023-09-13 09:47:56 +02:00
arch KVM: x86/mmu: Add "never" option to allow sticky disabling of nx_huge_pages 2023-09-13 09:47:56 +02:00
block blk-crypto: dynamically allocate fallback profile 2023-08-23 17:32:53 +02:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: jitter - correct health test during initialization 2023-07-19 16:36:19 +02:00
Documentation dt-bindings: sc16is7xx: Add property to change GPIO function 2023-09-06 21:25:32 +01:00
drivers Revert "PCI: tegra194: Enable support for 256 Byte payload" 2023-09-13 09:47:56 +02:00
fs Revert "fuse: in fuse_flush only wait if someone wants the return code" 2023-09-13 09:47:56 +02:00
include fs/nls: make load_nls() take a const parameter 2023-09-13 09:47:51 +02:00
init init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init() 2023-08-08 20:04:49 +02:00
io_uring io_uring: correct check for O_TMPFILE 2023-08-16 18:32:19 +02:00
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 tracing: Introduce pipe_cpumask to avoid race on trace_pipes 2023-09-13 09:47:55 +02:00
lib sbitmap: fix batching wakeup 2023-09-13 09:47:55 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm madvise:madvise_free_pte_range(): don't use mapcount() against large folio for sharing check 2023-08-30 14:52:42 +02:00
net net: Avoid address overwrite in kernel_connect 2023-09-13 09:47:56 +02:00
rust rust: macros: vtable: fix HAS_* redefinition (gen_const_name) 2023-08-23 17:32:36 +02:00
samples samples: ftrace: Save required argument registers in sample trampolines 2023-07-23 13:54:09 +02:00
scripts kbuild: rust: avoid creating temporary files 2023-07-27 08:57:06 +02:00
security security: keys: perform capable check only on privileged operations 2023-09-13 09:47:53 +02:00
sound ASoC: cs35l56: Add an ACPI match table 2023-09-13 09:47:55 +02:00
tools vmbus_testing: fix wrong python syntax for integer value comparison 2023-09-13 09:47:53 +02:00
usr initramfs: Check negative timestamp to prevent broken cpio archive 2023-04-16 17:37:01 +09:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-08-03 10:26:01 +02:00
.clang-format cxl for v6.4 2023-04-30 11:51:51 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 Ben Dooks 2023-06-19 13:19:35 -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 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 Networking fixes for 6.4-rc8, including fixes from ipsec, bpf, 2023-06-22 17:59:51 -07:00
Makefile Linux 6.4.15 2023-09-06 21:25:33 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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 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.