On Wed, Jun 21, 2023 at 05:52:52PM -0500, Limonciello, Mario wrote: > On 6/21/2023 5:28 PM, Bjorn Helgaas wrote: > > On Tue, Jun 20, 2023 at 09:04:51AM -0500, Mario Limonciello wrote: > > > Section 6.5.4 of the ACPI 6.4 spec describes how AML is unable to access > > > an OperationRegion unless `_REG` has been called. > > > ... > > > It is reported that ASMedia PCIe GPIO controllers fail > > > functional tests after the system has returning from suspend (S3 > > > or s2idle). This is because the BIOS checks whether the OSPM has > > > called the `_REG` method to determine whether it can interact > > > with the OperationRegion assigned to the device as part of the > > > other AML called for the device. > I double checked a BIOS debug log which shows ACPI calls > to confirm and didn't see a single _REG call for any device > before this patch across a boot/suspend/resume cycle. Sorry to follow up on this again. The commit log says these GPIO controllers fail functional tests after returning from suspend. Do those functional tests pass *before* suspend? If so, why? Without this patch, we *never* call _REG, so the fact that calling _REG when we return the device to D0 while resuming fixes something suggests that it might have been broken even before the suspend. Bjorn
