Hi, > From: Lukas Wunner [mailto:lu...@wunner.de] > Subject: Re: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the > namespace > > On Thu, Aug 10, 2017 at 12:34:23AM +0200, Rafael J. Wysocki wrote: > > --- linux-pm.orig/drivers/acpi/scan.c > > +++ linux-pm/drivers/acpi/scan.c > > @@ -2139,6 +2139,10 @@ int __init acpi_scan_init(void) > > acpi_get_spcr_uart_addr(); > > } > > > > + acpi_gpe_apply_masked_gpes(); > > + acpi_update_all_gpes(); > > + acpi_ec_ecdt_start(); > > + > > mutex_lock(&acpi_scan_lock); > > /* > > * Enumerate devices in the ACPI namespace. > > I notice this is called from a subsys_initcall(). We scan the PCI bus > much earlier in arch/x86/kernel/early-quirks.c and it would be possible > to identify presence of Thunderbolt host controllers in an early quirk > (using the method of pci_is_thunderbolt_attached()) and, if found, > enable their GPEs or all GPEs.
We have 2 choices here: 1. GPE is a part of device enumeration. GPE must be enabled one by one after making sure that all related bus/devices are powered on. But it seems there is no such relationship between GPE and bus/device in ACPI spec. However if Windows works in this way, we'll regress by applying this patch. 2. GPE is not a part of device enumeration. Then probably we can even move GPE enabling into acip_initialize_objects(), before calling acpi_ns_initialize_devices(). As after preparing ACPI namespace, _Lxx/_Exx is ready, and ACPI subsystem should be able to handle early GPEs. And ACPI subsystem's device enumeration starts from acpi_ns_initialize_devices(). So this patch should be correct in theory. ;) Thanks and best regards Lv > > Just as an aside in case your method doesn't work, I'm not affected by > this issue being a Mac user... ;-) > > Thanks, > > Lukas
