Re: [PATCH] hwmon: (acpi_power_meter) Install IPMI handler for Dell systems

From: Guenter Roeck <linux@roeck-us.net>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: jdelvare@suse.com, linux-hwmon@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] hwmon: (acpi_power_meter) Install IPMI handler for Dell systems
Date: Wed, 20 Dec 2023 15:49:38 -0800	[thread overview]
Message-ID: <5a81eda0-5044-4088-9aba-cf725e6fca9a@roeck-us.net> (raw)
In-Reply-To: <20231220051350.392350-1-kai.heng.feng@canonical.com>

On Wed, Dec 20, 2023 at 01:13:50PM +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 request module 'ipmi_si' which will load 'acpi_ipmi'
> and install the region handler accordingly.
> 
> [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>
> ---
>  drivers/hwmon/acpi_power_meter.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
> index 703666b95bf4..b9db53166bc9 100644
> --- a/drivers/hwmon/acpi_power_meter.c
> +++ b/drivers/hwmon/acpi_power_meter.c
> @@ -882,6 +882,8 @@ static int acpi_power_meter_add(struct acpi_device *device)
>  	strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
>  	strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
>  	device->driver_data = resource;
> +	if (dmi_match(DMI_SYS_VENDOR, "Dell Inc."))
> +		request_module("ipmi_si");
>  

This looks like a terrible hack to me. Is there precedent of similar hacks
elsewhere showing that this is the "way to go" ?

Guenter

>  	res = read_capabilities(resource);
>  	if (res)
> -- 
> 2.34.1
> 