From 670e98a34a9e44cd384bafbda681c8c8e072b714 Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng Date: Wed, 20 Mar 2024 16:43:16 +0800 Subject: ACPI: IPMI: Add helper to wait for when SMI is selected 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 --- drivers/acpi/acpi_ipmi.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'drivers/acpi') 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, -- cgit v1.2.3