On Fri, Jan 06, 2017 at 02:21:11AM +0100, Rafael J. Wysocki wrote: > On Thursday, January 05, 2017 03:42:20 PM Lukas Wunner wrote: > > On Wed, Jan 04, 2017 at 10:09:54PM +0100, Peter Wu wrote: > > > [ Help/ideas are welcome, I suspect that these failures to restore power > > > on laptops designed for Win8+ all have the same cause, related to some > > > unknown interaction between ACPI and PCI. Some links: > > > https://bugzilla.kernel.org/show_bug.cgi?id=190861 > > > https://bugzilla.kernel.org/show_bug.cgi?id=156341 ] > > > > Looking at Kilian's acpidump again I notice that the methods to power > > the GPU on or off (GPON / GPOF) are called from two places: > > > > - From the _PS0 and _PS3 methods of the GPU and > > - from the _PR3 power resource of the root port above the GPU. > > > > In the former case they're called for pre Windows 2013 or if VDAD is true. > > In the latter case they're called unconditionally but GPOF becomes a no-op > > in the pre Windows 2013 case. > > > > This means that GPOF would be executed *twice* on Windows 2013+ if VDAD > > is true. I could imagine this to cause issues. > > Right. Exactly my observation (http://marc.info/?l=linux-pci&m=148362622326066&w=2). > > So on (newer) Windows something is done in order to make it work in addition to > the _PR3 _OSC handshake. > > So, I'd like to try to follow the Mika's suggestion to use the response we get > from the _OSC handshake for \_SB and if that says "no _PR3", ignore power > resources for PCIe ports at least. Kilian send the dmesg back to me and unfortunately the BIOS on that machine acks use of _PR3: [ 0.699776] ACPI: Added _OSI(Module Device) [ 0.699777] ACPI: Added _OSI(Processor Device) [ 0.699777] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.699778] ACPI: Added _OSI(Processor Aggregator Device) [ 0.699783] ACPI : EC: EC started [ 0.700466] ACPI: \: Used as first EC [ 0.700467] ACPI: \: GPE=0x11, EC_CMD/EC_SC=0x66, EC_DATA=0x62 [ 0.700468] ACPI: \: Used as boot ECDT EC to handle transactions [ 0.703905] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored [ 0.880246] ACPI: \_SB_: Supported caps: 0x0000009f [ 0.880278] ACPI: \_SB_: Acked caps: 0x0000009f (_PR3: on) So ignoring _PR3 based on that will not solve the issue :-( -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
