On 5/16/2023 12:59 AM, Mika Westerberg wrote:
+Rafael
Hi Mario,
On Mon, May 15, 2023 at 06:15:15PM -0500, Mario Limonciello wrote:
Using an XHCI device to wakeup the system from s2idle fails when
that XHCI device is connected to a USB-C port for an AMD USB4
router.
Due to commit 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during
suspend") all root port go into D3 during s2idle.
When the root ports are in D3 over s2idle it's not possible for the
platform firmware to properly identify the wakeup source.
As a user presses a key on a keyboard the APU will exit
hardware sleep, but no wake source will be active so the kernel will
let the APU enter back into a hardware sleep state.
Here is an example of that sequence of events. The USB keyboard was
pressed after 11.9 seconds, and then a GPIO was triggered after
another 12 seconds.
```
PM: suspend-to-idle
ACPI: EC: ACPI EC GPE status set
ACPI: PM: Rearming ACPI SCI for wakeup
amd_pmc AMDI0007:00: SMU idlemask s0i3: 0x8fff9eb5
Timekeeping suspended for 11.985 seconds
PM: Triggering wakeup from IRQ 9
ACPI: EC: ACPI EC GPE status set
ACPI: EC: ACPI EC GPE dispatched
ACPI: EC: ACPI EC work flushed
ACPI: EC: ACPI EC work flushed
ACPI: PM: Rearming ACPI SCI for wakeup
amd_pmc AMDI0007:00: SMU idlemask s0i3: 0x8fff9eb5
PM: Triggering wakeup from IRQ 9
ACPI: EC: ACPI EC GPE status set
ACPI: PM: Rearming ACPI SCI for wakeup
amd_pmc AMDI0007:00: SMU idlemask s0i3: 0x8fff9eb5
Timekeeping suspended for 12.916 seconds
PM: Triggering wakeup from IRQ 9
PM: Triggering wakeup from IRQ 7
ACPI: EC: ACPI EC GPE status set
ACPI: EC: ACPI EC GPE dispatched
ACPI: EC: ACPI EC work flushed
ACPI: PM: Wakeup after ACPI Notify sync
PM: resume from suspend-to-idle
```
If the root ports are in D0 during s2idle, then the wake source is
properly identified and an IRQ is active for the root port, waking
the system up.
Here is the same sequence with root ports in D0. The USB keyboard
was pressed after 11 seconds.
```
PM: suspend-to-idle
ACPI: EC: ACPI EC GPE status set
ACPI: PM: Rearming ACPI SCI for wakeup
amd_pmc AMDI0007:00: SMU idlemask s0i3: 0x8fff9eb5
Timekeeping suspended for 11.138 seconds
PM: Triggering wakeup from IRQ 9
ACPI: PM: ACPI non-EC GPE wakeup
PM: resume from suspend-to-idle
PM: Triggering wakeup from IRQ 40
```
Comparing registers between Linux and Windows 11 this behavior to put root
ports into D3 at suspend is unique to Linux. Windows does not put the
root ports into D3 over Modern Standby.
Are you sure this is the case? Leaving the root port in D0 would mean
its power resource is left on and that would leave the whole USB4 domain
on consuming quite a lot of power.
Right - I had the same thought, but at least for AMD after the hardware
enters into s2idle
the platform does some internal management of power domains.
The root ports involved are supposed
to support PME from the D3hot/cold (this is what they advertise in their
config spaces) which should allow the OS to move the port into low power
states. Of course the PME from D3cold in general needs some ACPI support
(typically a GPE) in the BIOS.
AFAICT the actual issue is entirely a wakeup platform firmware
sequencing issue
while in a hardware sleep state and not PMEs.
It's only exposed by putting the root ports into D3 over s2idle.
As an experiment on an unpatched kernel if I avoid letting amd-pmc bind
then the
hardware will never enter a hardware sleep state over Linux s2idle and
this issue
doesn't occur.
That shows that PMEs *do* work from D3cold.
With all of this I have to wonder if the Windows behavior of what to do
with the root
ports is tied to the uPEP requirements specified in the firmware.
Linux doesn't do any enforcement or adjustments from what uPEP indicates.
The uPEP constraints for the root port in question in an affected AMD
system has:
Package (0x04)
{
Zero,
"\\_SB.PCI0.GP19",
Zero,
Zero
},
AMD's parsing is through 'lpi_device_get_constraints_amd' so that
structure shows
as not enabled and doesn't specify any D-state requirements.
What do they specify for Intel on a matching root port?
As this policy change to put root ports into D3 if they're manufactured
after 2015 was originally introduced for Intel systems narrow it down to
only apply there.
Reported-by: Iain Lane <iain@xxxxxxxxxxxxxxxxxxx>
Closes: https://forums.lenovo.com/t5/Ubuntu/Z13-can-t-resume-from-suspend-with-external-USB-keyboard/m-p/5217121
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/pci/pci.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5ede93222bc1..7d1b078b8d40 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3010,12 +3010,17 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
if (dmi_check_system(bridge_d3_blacklist))
return false;
+#ifdef CONFIG_X86
/*
- * It should be safe to put PCIe ports from 2015 or newer
- * to D3.
+ * It should be safe to put PCIe ports from Intel systems
+ * from 2015 or newer to D3.
+ * Windows 11 does not do this over Modern Standby and this is
+ * known to cause problems with s2idle on some AMD systems.
*/
- if (dmi_get_bios_year() >= 2015)
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
Can't we then check here AMD case instead? Then generic case would be to
support according what the port announces.
Right; that was my original patch, but given the Windows behavior I
figured it was better
to discuss if the original patch was actually correct or not.
