Re: [PATCH v2] hwmon: (acpi_power_meter) Ensure IPMI space handler is ready on Dell systems

[Armin Wolf <W_Armin@gmx.de>]

Am 27.12.23 um 05:04 schrieb Kai-Heng Feng:

> The following error can be observed at boot:
> [    3.717920] ACPI Error: No handler for Region [SYSI] (00000000ab9e62c5) [IPMI] (20230628/evregion-130)
> [    3.717928] ACPI Error: Region IPMI (ID=7) has no handler (20230628/exfldio-261)
>
> [    3.717936] No Local Variables are initialized for Method [_GHL]
>
> [    3.717938] No Arguments are initialized for method [_GHL]
>
> [    3.717940] ACPI Error: Aborting method \_SB.PMI0._GHL due to previous error (AE_NOT_EXIST) (20230628/psparse-529)
> [    3.717949] ACPI Error: Aborting method \_SB.PMI0._PMC due to previous error (AE_NOT_EXIST) (20230628/psparse-529)
> [    3.717957] ACPI: \_SB_.PMI0: _PMC evaluation failed: AE_NOT_EXIST
>
> On Dell systems several methods of acpi_power_meter access variables in
> IPMI region [0], so wait until IPMI space handler is installed by
> acpi_ipmi and also wait until SMI is selected to make the space handler
> fully functional.

Hi,

could it be that the ACPI firmware expects us to support the ACPI SPMI table?
The ACPI SPMI table contains a description of the IPMI interface used by the platform,
and its purpose seems to be similar to the ACPI ECDT table in that it allows the OS
to access IPMI resources before all ACPI namespaces are enumerated.

Adding support for this table would solve this problem without stalling the boot
process by waiting for the ACPI IPMI device to probe. It would also avoid any issues
should the ACPI IPMI device be removed later.

Armin Wolf

>
> [0] https://www.dell.com/support/manuals/en-us/redhat-enterprise-linux-v8.0/rhel8_rn_pub/advanced-configuration-and-power-interface-acpi-error-messages-displayed-in-dmesg?guid=guid-0d5ae482-1977-42cf-b417-3ed5c3f5ee62
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v2:
>   - Use completion instead of request_module().
>
>   drivers/acpi/acpi_ipmi.c         | 13 ++++++++++++-
>   drivers/hwmon/acpi_power_meter.c |  4 ++++
>   include/acpi/acpi_bus.h          |  4 ++++
>   3 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c
> index 0555f68c2dfd..2ea8b7e6cebf 100644
> --- a/drivers/acpi/acpi_ipmi.c
> +++ b/drivers/acpi/acpi_ipmi.c
> @@ -23,6 +23,8 @@ MODULE_LICENSE("GPL");
>   #define IPMI_TIMEOUT			(5000)
>   #define ACPI_IPMI_MAX_MSG_LENGTH	64
>
> +static struct completion smi_selected;
> +
>   struct acpi_ipmi_device {
>   	/* the device list attached to driver_data.ipmi_devices */
>   	struct list_head head;
> @@ -463,8 +465,10 @@ 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(&smi_selected);
> +	}
>   	list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
>   	mutex_unlock(&driver_data.ipmi_lock);
>
> @@ -578,10 +582,17 @@ acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
>   	return status;
>   }
>
> +void wait_for_acpi_ipmi(void)
> +{
> +	wait_for_completion_interruptible_timeout(&smi_selected, 2 * HZ);
> +}
> +EXPORT_SYMBOL_GPL(wait_for_acpi_ipmi);
> +
>   static int __init acpi_ipmi_init(void)
>   {
>   	int result;
>   	acpi_status status;
> +	init_completion(&smi_selected);
>
>   	if (acpi_disabled)
>   		return 0;
> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
> index 703666b95bf4..acaf1ae68dc8 100644
> --- a/drivers/hwmon/acpi_power_meter.c
> +++ b/drivers/hwmon/acpi_power_meter.c
> @@ -883,6 +883,10 @@ static int acpi_power_meter_add(struct acpi_device *device)
>   	strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
>   	device->driver_data = resource;
>
> +	if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.") &&
> +	    acpi_dev_get_first_match_dev("IPI0001", NULL, -1))
> +		wait_for_acpi_ipmi();
> +
>   	res = read_capabilities(resource);
>   	if (res)
>   		goto exit_free;
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 1216d72c650f..ed59fb89721e 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -655,6 +655,7 @@ bool acpi_device_override_status(struct acpi_device *adev, unsigned long long *s
>   bool acpi_quirk_skip_acpi_ac_and_battery(void);
>   int acpi_install_cmos_rtc_space_handler(acpi_handle handle);
>   void acpi_remove_cmos_rtc_space_handler(acpi_handle handle);
> +void wait_for_acpi_ipmi(void);
>   #else
>   static inline bool acpi_device_override_status(struct acpi_device *adev,
>   					       unsigned long long *status)
> @@ -672,6 +673,9 @@ static inline int acpi_install_cmos_rtc_space_handler(acpi_handle handle)
>   static inline void acpi_remove_cmos_rtc_space_handler(acpi_handle handle)
>   {
>   }
> +static inline void wait_for_acpi_ipmi(void)
> +{
> +}
>   #endif
>
>   #if IS_ENABLED(CONFIG_X86_ANDROID_TABLETS)