> -----Original Message----- > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Bjorn Helgaas > Sent: Thursday, January 18, 2018 11:11 AM > To: Hans de Goede <hdegoede@xxxxxxxxxx> > Cc: Rafael J . Wysocki <rjw@xxxxxxxxxxxxx>; Len Brown <lenb@xxxxxxxxxx>; > Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; Moore, Robert > <robert.moore@xxxxxxxxx>; Zheng, Lv <lv.zheng@xxxxxxxxx>; linux- > acpi@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; devel@xxxxxxxxxx > Subject: Re: ACPI: Do not call _STA on battery devices with unmet dependencies > > On Thu, Jan 18, 2018 at 05:03:55PM +0100, Hans de Goede wrote: Hi Hans, > > Hi All, > > > > 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. Could you explain why _STA method using an I2C OpRegion is problematic? Thanks, Erik > > > > Here is the DSDT of the device I'm seeing this on: > > https://fedorapeople.org/~jwrdegoede/toshiba-click-mini-dsdt.dsl > > This looks like interesting info, but (a) this link isn't mentioned in the actual > patches, and (b) it's conceivable that fedorapeople.org could go away someday. > If this were a PCI series, I would suggest opening a report at bugzilla.kernel.org, > attaching the DSL there, and including the link in the patch changelog. > > > 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 commit is a preparation commit for making the ACPICA changes > > in the 4th commit, this commit is necessary to not break things after > > the ACPICA changes. > > > > The second 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 third 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 fourth 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 > > 4 patches in place we've fixed all 4 too early _STA calls. > > > > Regards, > > > > Hans > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" > > in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo > > info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of > a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at > http://vger.kernel.org/majordomo-info.html
