On Tue, Jan 9, 2024 at 5:12 AM Kai-Heng Feng
<kai.heng.feng@xxxxxxxxxxxxx> wrote:
>
> On Dell servers, many APCI methods of acpi_power_meter module evaluate
> variables inside IPMI region, so the region handler needs to be
> installed. In addition to that, the handler needs to be fully
> functional, and that depends on SMI being selected.
>
> So add a helper to let acpi_power_meter know when the handler is
> installed and ready to be used.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
and I'm expecting this to be routed along with patch [2/2] that has
been posted elsewhere.
> ---
> v4:
> - Wording.
> - Define and comment on timeout value.
> - Move the completion to driver_data.
> - Remove the tenary operator.
>
> v3:
> - New patch.
>
> drivers/acpi/acpi_ipmi.c | 23 ++++++++++++++++++++++-
> include/acpi/acpi_bus.h | 5 +++++
> 2 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c
> index 0555f68c2dfd..5fba4dab5d08 100644
> --- a/drivers/acpi/acpi_ipmi.c
> +++ b/drivers/acpi/acpi_ipmi.c
> @@ -22,6 +22,8 @@ MODULE_LICENSE("GPL");
> /* the IPMI timeout is 5s */
> #define IPMI_TIMEOUT (5000)
> #define ACPI_IPMI_MAX_MSG_LENGTH 64
> +/* 2s should be suffient for SMI being selected */
> +#define ACPI_IPMI_SMI_SELECTION_TIMEOUT (2 * HZ)
>
> struct acpi_ipmi_device {
> /* the device list attached to driver_data.ipmi_devices */
> @@ -54,6 +56,7 @@ struct ipmi_driver_data {
> * to this selected global IPMI system interface.
> */
> struct acpi_ipmi_device *selected_smi;
> + struct completion smi_selection_done;
> };
>
> struct acpi_ipmi_msg {
> @@ -463,8 +466,10 @@ static void ipmi_register_bmc(int iface, struct device *dev)
> if (temp->handle == handle)
> goto err_lock;
> }
> - if (!driver_data.selected_smi)
> + if (!driver_data.selected_smi) {
> driver_data.selected_smi = ipmi_device;
> + complete(&driver_data.smi_selection_done);
> + }
> list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
> mutex_unlock(&driver_data.ipmi_lock);
>
> @@ -578,6 +583,20 @@ acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
> return status;
> }
>
> +int acpi_wait_for_acpi_ipmi(void)
> +{
> + long ret;
> +
> + ret = wait_for_completion_interruptible_timeout(&driver_data.smi_selection_done,
> + ACPI_IPMI_SMI_SELECTION_TIMEOUT);
> +
> + if (ret <= 0)
> + return -ETIMEDOUT;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(acpi_wait_for_acpi_ipmi);
> +
> static int __init acpi_ipmi_init(void)
> {
> int result;
> @@ -586,6 +605,8 @@ static int __init acpi_ipmi_init(void)
> if (acpi_disabled)
> return 0;
>
> + init_completion(&driver_data.smi_selection_done);
> +
> status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
> ACPI_ADR_SPACE_IPMI,
> &acpi_ipmi_space_handler,
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 1216d72c650f..afa6e4d4bf46 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -821,11 +821,16 @@ static inline void acpi_put_acpi_dev(struct acpi_device *adev)
> {
> acpi_dev_put(adev);
> }
> +
> +int acpi_wait_for_acpi_ipmi(void);
> +
> #else /* CONFIG_ACPI */
>
> static inline int register_acpi_bus_type(void *bus) { return 0; }
> static inline int unregister_acpi_bus_type(void *bus) { return 0; }
>
> +static inline int acpi_wait_for_acpi_ipmi(void) { return 0; }
> +
> #endif /* CONFIG_ACPI */
>
> #endif /*__ACPI_BUS_H__*/
> --
