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Niklas Cassel a38719e315 ata: libata: avoid superfluous disk spin down + spin up during hibernation
A user reported that commit aa3998dbeb ("ata: libata-scsi: Disable scsi
device manage_system_start_stop") introduced a spin down + immediate spin
up of the disk both when entering and when resuming from hibernation.
This behavior was not there before, and causes an increased latency both
when entering and when resuming from hibernation.

Hibernation is done by three consecutive PM events, in the following order:
1) PM_EVENT_FREEZE
2) PM_EVENT_THAW
3) PM_EVENT_HIBERNATE

Commit aa3998dbeb ("ata: libata-scsi: Disable scsi device
manage_system_start_stop") modified ata_eh_handle_port_suspend() to call
ata_dev_power_set_standby() (which spins down the disk), for both event
PM_EVENT_FREEZE and event PM_EVENT_HIBERNATE.

Documentation/driver-api/pm/devices.rst, section "Entering Hibernation",
explicitly mentions that PM_EVENT_FREEZE does not have to be put the device
in a low-power state, and actually recommends not doing so. Thus, let's not
spin down the disk on PM_EVENT_FREEZE. (The disk will instead be spun down
during the subsequent PM_EVENT_HIBERNATE event.)

This way, PM_EVENT_FREEZE will behave as it did before commit aa3998dbeb
("ata: libata-scsi: Disable scsi device manage_system_start_stop"), while
PM_EVENT_HIBERNATE will continue to spin down the disk.

This will avoid the superfluous spin down + spin up when entering and
resuming from hibernation, while still making sure that the disk is spun
down before actually entering hibernation.

Cc: stable@vger.kernel.org # v6.6+
Fixes: aa3998dbeb ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20241008135843.1266244-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
2024-10-09 16:21:19 +02:00
arch ARM64: 2024-10-06 10:53:28 -07:00
block block-6.12-20241004 2024-10-04 10:43:44 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
Documentation platform-drivers-x86 for v6.12-2 2024-10-06 11:11:01 -07:00
drivers ata: libata: avoid superfluous disk spin down + spin up during hibernation 2024-10-09 16:21:19 +02:00
fs bcachefs fixes for 6.12-rc2 2024-10-05 15:18:04 -07:00
include Power management fixes for 6.12-rc2 2024-10-04 11:57:15 -07:00
init cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig 2024-09-26 21:27:27 +02:00
io_uring io_uring/net: harden multishot termination case for recv 2024-09-30 08:26:59 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel Various fixes for tracing: 2024-10-04 12:11:06 -07:00
lib slab fixes for 6.12-rc1 2024-10-04 12:05:39 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm, slab: suppress warnings in test_leak_destroy kunit test 2024-10-02 16:28:46 +02:00
net Including fixes from ieee802154, bluetooth and netfilter. 2024-10-03 09:44:00 -07:00
rust rust: kunit: use C-string literals to clean warning 2024-10-01 23:46:42 +02:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts kbuild: deb-pkg: Remove blank first line from maint scripts 2024-10-07 02:36:38 +09:00
security hardening fixes for v6.12-rc2 2024-10-05 10:19:14 -07:00
sound sound fixes for 6.12-rc2 2024-10-04 11:29:46 -07:00
tools ARM64: 2024-10-06 10:53:28 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt x86: 2024-09-28 09:20:14 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +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 Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap Summary 2024-09-24 11:08:40 -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: Mark powerpc spufs as orphaned 2024-08-19 21:27:56 +10:00
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 platform-drivers-x86 for v6.12-2 2024-10-06 11:11:01 -07:00
Makefile Linux 6.12-rc2 2024-10-06 15:32:27 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -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 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.