Re: [PATCH v2 0/5] ACPI: Do not call _STA on battery devices with unmet dependencies

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On Monday, January 22, 2018 9:51:30 AM CET Hans de Goede wrote:
> Hi All,
> 
> Here is v2 of this set, new in v2 is the addressing of Bjorn's comments
> to the "PCI: acpiphp_ibm: prepare for acpi_get_object_info no longer
> returning status" patch and a new patch (the first patch in v2) which
> exports acpi_bus_get_status_handle() for use in modules as acpiphp_ibm
> will now depend on it.
> 
> Here is the old coverletter from v1 (adjusted for the new patch):
> 
> The ACPI code already contains quite a bit of code to not bind the
> ACPI-battery until all deps for an ACPI battery device have been met,
> but on some devices calling _STA before all deps are met is a problem
> too because the _STA method uses an i2c OpRegion there.
> 
> Here is the DSDT of the device I'm seeing this on:
> https://fedorapeople.org/~jwrdegoede/toshiba-click-mini-dsdt.dsl
> 
> This series modifies the kernel to not call _STA until all deps are met,
> mirroring the binding behavior of the battery driver.
> 
> Without this series a total of 32 ACPI errors get printend to the console
> on boot, there are 4 errors per _STA call, 2 battery devices on this
> system and 4 _STA calls per battery device.
> 
> The first 2 commits are preparation commits for making the ACPICA changes
> in the 4th commit, these commits are necessary to not break things after
> the ACPICA changes.
> 
> The 3th commit modifies acpi_bus_get_status to not call _STA on
> battery devices until all deps are met. This fixes 2 of the 4 too early
> _STA calls triggering these errors.
> 
> The 4th commit makes the device instantiation code use
> acpi_bus_get_status instead of acpi_bus_get_status_handle so that the
> code to get the initial status also does not makes 1 too early _STA call.
> 
> The 5th commit changes the ACPICA acpi_get_object_info function to not
> call _STA. Only 1 user (which is fixed in the first commit) cares about
> acpi_device_info.current_status. And the ACPICA code has this comment:
> 
>  * Note: This interface is intended to be used during the initial device
>  * discovery namespace traversal. Therefore, no complex methods can be
>  * executed, especially those that access operation regions. Therefore, do
>  * not add any additional methods that could cause problems in this area.
>  * Because of this reason support for the following methods has been removed:
>  * this was the fate of the _SUB method which was found to cause such
>  * problems and was removed (11/2015).
> 
> The described problems with the _SUB method clearly also apply to the _STA
> method, so removing it from acpi_get_object_info seems like it is the right
> thing to do here. This too fixes 1 too early _STA call, so that with all
> 5 patches in place we've fixed all 4 too early _STA calls.

I've applied [1-4/5] from this series.

The last one needs to go in via ACPICA anyway or we'll need to carry
a Linux-specific replacement for acpi_get_object_info().




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