Re: [PATCH 0/2] reboot-mode: Expose sysfs for registered reboot modes

[Bartosz Golaszewski]

On Sun, 16 Nov 2025 at 16:20, Shivendra Pratap
<shivendra.pratap@xxxxxxxxxxxxxxxx> wrote:
>
> The reboot-mode framework provides infrastructure for drivers that want
> to implement a userspace reboot command interface. However, there is
> currently no standardized way for userspace to discover the list of
> supported commands at runtime. This series introduces a sysfs interface
> in the reboot-mode framework to expose the list of supported reboot-mode
> commands to userspace. This will enable userspace tools to query
> available reboot modes using the sysfs interface.
>
> Example:
>   cat /sys/class/reboot-mode/<driver-name>/reboot_modes
>
> The series consists of two patches:
>   1. power: reset: reboot-mode: Expose sysfs for registered reboot_modes
>   2. Documentation: ABI: Add sysfs-class-reboot-mode-reboot_modes
>
> These patches were previously being reviewed as part of “vendor resets
> for PSCI SYSTEM_RESET2”, until v17. Following the suggestions from
> Bjorn, the reboot-mode sysfs patches have been split into a separate
> series here, for focused discussions and better alignment.
>
> Previous discussion on these patches:
> https://lore.kernel.org/all/20251109-arm-psci-system_reset2-vendor-reboots-v17-5-46e085bca4cc@xxxxxxxxxxxxxxxx/
> https://lore.kernel.org/all/20251109-arm-psci-system_reset2-vendor-reboots-v17-4-46e085bca4cc@xxxxxxxxxxxxxxxx/
>

When doing a split like this, please keep the versioning going. This
should be v18.

Bart

> Signed-off-by: Shivendra Pratap <shivendra.pratap@xxxxxxxxxxxxxxxx>
>
> Changes from previous version:
> By Bjyon
>  - class is made static const and moved on the stack and registered
>    using class_register.
>  - Renamed name of class variable from rb_class to reboot_mode_class –
>    Bart/ Bjyon
>  - Renamed function name to prefix reboot_mode* to better align naming
>    convention in reboot-mode.
>  - Changed reboot_mode_device as static in reboot struct and registered
>    using device_register.
>  - Used dev_groups, instead of creating the sysfs attr file manually.
>  - Continued the reboot-mode registration even if the sysfs creation
>    fails at reboot_mode_create_device.
>  - Used container of dev in show_reboot_modes to get the structure
>    pointer of reboot.
>
> By Bart
>  -Synchronize class registration, as there may be race in this lazy
> class_register.
>  -Remove inversion kind of logic and align the return path of
> show_reboot_modes
>
> Other changes
>  - reboot_dev is renamed to reboot_mode_device to align the naming
>    conventions.
>  - Keep a check on status of device_register with bool flag as
>    device_unregister should be called only if the registration was
>   successful.
>  - Add a dummy function reboot_mode_device_release to avoid warn in
>    driver unload path.
>  - Date and version change in ABI documentation.
>
> Link to previous series:
> https://lore.kernel.org/all/20251109-arm-psci-system_reset2-vendor-reboots-v17-0-46e085bca4cc@xxxxxxxxxxxxxxxx
>
> ---
> Shivendra Pratap (2):
>       Documentation: ABI: Add sysfs-class-reboot-mode-reboot_modes
>       power: reset: reboot-mode: Expose sysfs for registered reboot_modes
>
>  .../testing/sysfs-class-reboot-mode-reboot_modes   | 39 ++++++++++++
>  drivers/power/reset/reboot-mode.c                  | 72 ++++++++++++++++++++++
>  include/linux/reboot-mode.h                        |  3 +
>  3 files changed, 114 insertions(+)
> ---
> base-commit: 0f2995693867bfb26197b117cd55624ddc57582f
> change-id: 20251116-next-15nov_expose_sysfs-c0dbcf0d59da
>
> Best regards,
> --
> Shivendra Pratap <shivendra.pratap@xxxxxxxxxxxxxxxx>
>