Re: [PATCH v5 2/2] hwmon: (acpi_power_meter) Ensure IPMI space handler is ready on Dell systems

[Andy Shevchenko]

On Wed, Mar 20, 2024 at 04:43:17PM +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.
> 
> Since the dependency is inside BIOS's ASL code and it's not
> discoverable, so use this fixup is a hack to workaround BIOS issue.

..

> +	if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.")) {
> +		ipi_device = acpi_dev_get_first_match_dev("IPI0001", NULL, -1);
> +
> +		if (ipi_device) {
> +			if (acpi_wait_for_acpi_ipmi())
> +				dev_warn(&device->dev, "Waiting for ACPI IPMI timeout");
> +			acpi_dev_put(ipi_device);
> +		}

Can be written as

	if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.")) {
		ipi_device = acpi_dev_get_first_match_dev("IPI0001", NULL, -1);
		if (ipi_device && acpi_wait_for_acpi_ipmi())
			dev_warn(&device->dev, "Waiting for ACPI IPMI timeout");
		acpi_dev_put(ipi_device);

> +	}

-- 
With Best Regards,
Andy Shevchenko