linux-toradex.git/kernel/reboot.c, branch v6.6-rc5

kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode

2022-10-04T13:59:36+00:00

Add SYS_OFF_MODE_RESTART_PREPARE callbacks to be invoked before
a system restart.

Suggested-by: Dmitry Osipenko 
Reviewed-by: Dmitry Osipenko 
Signed-off-by: Kai-Heng Feng 
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki

Merge branch 'rework/kthreads' into for-linus

2022-06-23T17:11:28+00:00

Revert "printk: add functions to prefer direct printing"

2022-06-23T16:41:40+00:00

This reverts commit 2bb2b7b57f81255c13f4395ea911d6bdc70c9fe2.

The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.

It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.

printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.

Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20220623145157.21938-7-pmladek@suse.com

Revert "printk: Wait for the global console lock when the system is going down"

2022-06-23T16:41:40+00:00

This reverts commit b87f02307d3cfbda768520f0687c51ca77e14fc3.

The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.

It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.

printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.

Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20220623145157.21938-2-pmladek@suse.com

Merge tag 'printk-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2022-06-17T19:57:42+00:00

Pull printk fixes from Petr Mladek:
 "Make the global console_sem available for CPU that is handling panic()
  or shutdown.

  This is an old problem when an existing console lock owner might block
  console output, but it became more visible with the kthreads"

* tag 'printk-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Wait for the global console lock when the system is going down
  printk: Block console kthreads when direct printing will be required

Merge branch 'rework/kthreads' into for-linus

2022-06-17T14:36:48+00:00

printk: Wait for the global console lock when the system is going down

2022-06-15T20:04:15+00:00

There are reports that the console kthreads block the global console
lock when the system is going down, for example, reboot, panic.

First part of the solution was to block kthreads in these problematic
system states so they stopped handling newly added messages.

Second part of the solution is to wait when for the kthreads when
they are actively printing. It solves the problem when a message
was printed before the system entered the problematic state and
the kthreads managed to step in.

A busy waiting has to be used because panic() can be called in any
context and in an unknown state of the scheduler.

There must be a timeout because the kthread might get stuck or sleeping
and never release the lock. The timeout 10s is an arbitrary value
inspired by the softlockup timeout.

Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1
Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.com
Signed-off-by: Petr Mladek 
Tested-by: Paul E. McKenney 
Link: https://lore.kernel.org/r/20220615162805.27962-3-pmladek@suse.com

kernel/reboot: Fix powering off using a non-syscall code paths

2022-06-07T17:42:31+00:00

There are other methods of powering off machine than the reboot syscall.
Previously we missed to cover those methods and it created power-off
regression for some machines, like the PowerPC e500.

Fix this problem by moving the legacy sys-off handler registration to
the latest phase of power-off process and making the kernel_can_power_off()
check the legacy pm_power_off presence.

Tested-by: Michael Ellerman  # ppce500
Reported-by: Michael Ellerman  # ppce500
Fixes: da007f171fc9 ("kernel/reboot: Change registration order of legacy power-off handler")
Signed-off-by: Dmitry Osipenko 
Signed-off-by: Rafael J. Wysocki

kernel/reboot: Use static handler for register_platform_power_off()

2022-06-02T18:36:13+00:00

The register_platform_power_off() fails on m68k platform due to the
memory allocation error that happens at a very early boot time when
memory allocator isn't available yet. Fix it by using a static sys-off
handler for the platform-level power-off handlers.

Fixes: f0f7e5265b3b ("m68k: Switch to new sys-off handler API")
Reported-by: Geert Uytterhoeven 
Signed-off-by: Dmitry Osipenko 
Reviewed-by: Geert Uytterhoeven 
Tested-by: Geert Uytterhoeven 
Signed-off-by: Rafael J. Wysocki

Merge tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2022-05-30T18:37:26+00:00

Pull more power management updates from Rafael Wysocki:
 "These update the ARM cpufreq drivers and fix up the CPPC cpufreq
  driver after recent changes, update the OPP code and PM documentation
  and add power sequences support to the system reboot and power off
  code.

  Specifics:

   - Add Tegra234 cpufreq support (Sumit Gupta)

   - Clean up and enhance the Mediatek cpufreq driver (Wan Jiabing,
     Rex-BC Chen, and Jia-Wei Chang)

   - Fix up the CPPC cpufreq driver after recent changes (Zheng Bin,
     Pierre Gondois)

   - Minor update to dt-binding for Qcom's opp-v2-kryo-cpu (Yassine
     Oudjana)

   - Use list iterator only inside the list_for_each_entry loop
     (Xiaomeng Tong, and Jakob Koschel)

   - New APIs related to finding OPP based on interconnect bandwidth
     (Krzysztof Kozlowski)

   - Fix the missing of_node_put() in _bandwidth_supported() (Dan
     Carpenter)

   - Cleanups (Krzysztof Kozlowski, and Viresh Kumar)

   - Add Out of Band mode description to the intel-speed-select utility
     documentation (Srinivas Pandruvada)

   - Add power sequences support to the system reboot and power off code
     and make related platform-specific changes for multiple platforms
     (Dmitry Osipenko, Geert Uytterhoeven)"

* tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (60 commits)
  cpufreq: CPPC: Fix unused-function warning
  cpufreq: CPPC: Fix build error without CONFIG_ACPI_CPPC_CPUFREQ_FIE
  Documentation: admin-guide: PM: Add Out of Band mode
  kernel/reboot: Change registration order of legacy power-off handler
  m68k: virt: Switch to new sys-off handler API
  kernel/reboot: Add devm_register_restart_handler()
  kernel/reboot: Add devm_register_power_off_handler()
  soc/tegra: pmc: Use sys-off handler API to power off Nexus 7 properly
  reboot: Remove pm_power_off_prepare()
  regulator: pfuze100: Use devm_register_sys_off_handler()
  ACPI: power: Switch to sys-off handler API
  memory: emif: Use kernel_can_power_off()
  mips: Use do_kernel_power_off()
  ia64: Use do_kernel_power_off()
  x86: Use do_kernel_power_off()
  sh: Use do_kernel_power_off()
  m68k: Switch to new sys-off handler API
  powerpc: Use do_kernel_power_off()
  xen/x86: Use do_kernel_power_off()
  parisc: Use do_kernel_power_off()
  ...