Re: [PATCH v7 08/16] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug

[Hanjun Guo]

On 2024/4/18 21:54, Jonathan Cameron wrote:
> From: James Morse <james.morse@xxxxxxx>
>
> struct acpi_scan_handler has a detach callback that is used to remove
> a driver when a bus is changed. When interacting with an eject-request,
> the detach callback is called before _EJ0.
>
> This means the ACPI processor driver can't use _STA to determine if a
> CPU has been made not-present, or some of the other _STA bits have been
> changed. acpi_processor_remove() needs to know the value of _STA after
> _EJ0 has been called.
>
> Add a post_eject callback to struct acpi_scan_handler. This is called
> after acpi_scan_hot_remove() has successfully called _EJ0. Because
> acpi_scan_check_and_detach() also clears the handler pointer,
> it needs to be told if the caller will go on to call
> acpi_bus_post_eject(), so that acpi_device_clear_enumerated()
> and clearing the handler pointer can be deferred.
> An extra flag is added to flags field introduced in the previous
> patch to achieve this.
>
> Signed-off-by: James Morse <james.morse@xxxxxxx>
> Reviewed-by: Joanthan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
> Tested-by: Miguel Luis <miguel.luis@xxxxxxxxxx>
> Tested-by: Vishnu Pajjuri <vishnu@xxxxxxxxxxxxxxxxxxxxxx>
> Tested-by: Jianyong Wu <jianyong.wu@xxxxxxx>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

Reviewed-by: Hanjun Guo <guohanjun@xxxxxxxxxx>