From 55307af25a93a36615857e92b719dae09213bd11 Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng Date: Wed, 27 Mar 2024 22:30:43 +0800 Subject: [PATCH] ACPI: IPMI: Add helper to wait for when SMI is selected BugLink: https://bugs.launchpad.net/bugs/2059263 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 Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20240320084317.366853-1-kai.heng.feng@canonical.com Signed-off-by: Guenter Roeck (cherry picked from commit b72cb1769b8419060651cf5b0c271f3872e88748 linux-next) Signed-off-by: Kai-Heng Feng Signed-off-by: Paolo Pisati --- 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 @@ out_msg: 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 e4d24d3f9abb..f7cdce76e649 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -976,11 +976,16 @@ 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__*/