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Maciej S. Szmigiero 2f0fd471cc net: wwan: iosm: Fix hibernation by re-binding the driver around it
[ Upstream commit 0b6f6593aa ]

Currently, the driver is seriously broken with respect to the
hibernation (S4): after image restore the device is back into
IPC_MEM_EXEC_STAGE_BOOT (which AFAIK means bootloader stage) and needs
full re-launch of the rest of its firmware, but the driver restore
handler treats the device as merely sleeping and just sends it a
wake-up command.

This wake-up command times out but device nodes (/dev/wwan*) remain
accessible.
However attempting to use them causes the bootloader to crash and
enter IPC_MEM_EXEC_STAGE_CD_READY stage (which apparently means "a crash
dump is ready").

It seems that the device cannot be re-initialized from this crashed
stage without toggling some reset pin (on my test platform that's
apparently what the device _RST ACPI method does).

While it would theoretically be possible to rewrite the driver to tear
down the whole MUX / IPC layers on hibernation (so the bootloader does
not crash from improper access) and then re-launch the device on
restore this would require significant refactoring of the driver
(believe me, I've tried), since there are quite a few assumptions
hard-coded in the driver about the device never being partially
de-initialized (like channels other than devlink cannot be closed,
for example).
Probably this would also need some programming guide for this hardware.

Considering that the driver seems orphaned [1] and other people are
hitting this issue too [2] fix it by simply unbinding the PCI driver
before hibernation and re-binding it after restore, much like
USB_QUIRK_RESET_RESUME does for USB devices that exhibit a similar
problem.

Tested on XMM7360 in HP EliteBook 855 G7 both with s2idle (which uses
the existing suspend / resume handlers) and S4 (which uses the new code).

[1]: https://lore.kernel.org/all/c248f0b4-2114-4c61-905f-466a786bdebb@leemhuis.info/
[2]:
https://github.com/xmm7360/xmm7360-pci/issues/211#issuecomment-1804139413

Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Link: https://patch.msgid.link/e60287ebdb0ab54c4075071b72568a40a75d0205.1736372610.git.mail@maciej.szmigiero.name
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-02-17 09:40:08 +01:00
arch x86/amd_nb: Restrict init function to AMD-based systems 2025-02-17 09:40:03 +01:00
block partitions: ldm: remove the initial kernel-doc notation 2025-02-08 09:51:43 +01:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: ecc - Prevent ecc_digits_from_bytes from reading too many bytes 2025-01-09 13:31:52 +01:00
Documentation dt-bindings: mfd: bd71815: Fix rsense and typos 2025-02-08 09:51:52 +01:00
drivers net: wwan: iosm: Fix hibernation by re-binding the driver around it 2025-02-17 09:40:08 +01:00
fs btrfs: convert BUG_ON in btrfs_reloc_cow_block() to proper error handling 2025-02-17 09:40:03 +01:00
include net/mlx5: use do_aux_work for PHC overflow checks 2025-02-17 09:40:08 +01:00
init Compiler Attributes: disable __counted_by for clang < 19.1.3 2024-12-09 10:32:46 +01:00
io_uring io_uring/uring_cmd: use cached cmd_op in io_uring_cmd_sock() 2025-02-08 09:52:33 +01:00
ipc ipc: fix memleak if msg_init_ns failed in create_ipc_ns 2024-12-09 10:32:54 +01:00
kernel printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX 2025-02-17 09:40:04 +01:00
lib lockdep: Fix upper limit for LOCKDEP_*_BITS configs 2025-02-17 09:40:03 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm cachestat: fix page cache statistics permission checking 2025-02-01 18:37:54 +01:00
net Bluetooth: MGMT: Fix slab-use-after-free Read in mgmt_remove_adv_monitor_sync 2025-02-17 09:40:08 +01:00
rust rust: macros: fix documentation of the paste! macro 2024-12-09 10:32:25 +01:00
samples samples/landlock: Fix possible NULL dereference in parse_path() 2025-02-08 09:51:57 +01:00
scripts kbuild: switch from lz4c to lz4 for compression 2025-02-08 09:52:35 +01:00
security tomoyo: don't emit warning in tomoyo_write_control() 2025-02-17 09:40:07 +01:00
sound ALSA: usb-audio: Add delay quirk for iBasso DC07 Pro 2025-02-08 09:52:36 +01:00
tools ktest.pl: Check kernelrelease return in get_version 2025-02-08 09:52:36 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock 2024-10-04 16:29:47 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.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: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Remove *.orig pattern from .gitignore 2024-10-04 16:29:44 +02:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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 membarrier: riscv: Add full memory barrier in switch_mm() 2024-09-12 11:11:45 +02:00
Makefile Linux 6.6.77 2025-02-11 09:37:33 +01:00
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.