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Sender: Guenter Roeck <groeck7@gmail.com>
Date: Wed, 27 Dec 2023 13:57:59 -0800
From: Guenter Roeck <linux@roeck-us.net>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: jdelvare@suse.com, "Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>, Robert Moore <robert.moore@intel.com>,
	linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-hwmon@vger.kernel.org, acpica-devel@lists.linux.dev
Subject: Re: [PATCH v2] hwmon: (acpi_power_meter) Ensure IPMI space handler
 is ready on Dell systems
Message-ID: <40694180-cc87-4ae2-9929-8451d43f428d@roeck-us.net>
References: <20231227040401.548977-1-kai.heng.feng@canonical.com>
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In-Reply-To: <20231227040401.548977-1-kai.heng.feng@canonical.com>

On Wed, Dec 27, 2023 at 12:04:00PM +0800, Kai-Heng Feng wrote:
> 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.
> 
> [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 ++++

This needs to be split into two patches.

>  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);

wait_for_completion_interruptible_timeout) returns an error code which
should be returned to the caller.

> +}
> +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();

wait_for_acpi_ipmi() should return an error code which
should be handled here.

> +
>  	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)
> +{
> +}

Something with the conditional is wrong. See 0-day report.

Guenter
>  #endif
>  
>  #if IS_ENABLED(CONFIG_X86_ANDROID_TABLETS)
> -- 
> 2.34.1
> 
>