On Wed, Sep 11, 2024 at 02:38:20PM -0500, Mario Limonciello wrote: > On 9/11/2024 14:16, Mario Limonciello wrote: > > On 9/11/2024 14:05, Bjorn Helgaas wrote: > > > On Fri, Jul 12, 2024 at 02:24:11PM +0800, Kai-Heng Feng wrote: > > > > Some laptops wake up after poweroff when HP Thunderbolt Dock G4 is > > > > connected. > > > > > > > > The following error message can be found during shutdown: > > > > pcieport 0000:00:1d.0: AER: Correctable error message received > > > > from 0000:09:04.0 > > > > pcieport 0000:09:04.0: PCIe Bus Error: severity=Correctable, > > > > type=Data Link Layer, (Receiver ID) > > > > pcieport 0000:09:04.0: device [8086:0b26] error > > > > status/mask=00000080/00002000 > > > > pcieport 0000:09:04.0: [ 7] BadDLLP > > > > > > > > Calling aer_remove() during shutdown can quiesce the error message, > > > > however the spurious wakeup still happens. > > > > > > > > The issue won't happen if the device is in D3 before system shutdown, so > > > > putting device to low power state before shutdown to solve the issue. > > > > > > > > I don't have a sniffer so this is purely guesswork, however I believe > > > > putting device to low power state it's the right thing to do. > > > > > > My objection here is that we don't have an explanation of why this > > > should matter or a pointer to any spec language about this situation, > > > so it feels a little bit random. > > > > > > I suppose the problem wouldn't happen if AER interrupts were disabled? > > > We already do disable them in aer_suspend(), but maybe that's not used > > > in the shutdown path? > > > > > > My understanding is that .shutdown() should turn off device interrupts > > > and stop DMA. So maybe we need an aer_shutdown() that disables > > > interrupts? > > > > > > > IMO I see this commit as two problems with the same solution. > > > > I don't doubt that cleaning up AER interrupts in the shutdown path would > > help AER messages, but you really don't "want" devices to be in D0 when > > the system is "off" because even if the system is off some rails are > > still active and the device might still be powered. > > > > A powered device could cause interrupts (IE a spurious wakeup). > > It's a bit of a stretch, but ACPI 7.4.2.5 and 7.4.2.6 are the closest > corollary to a spec I can find. > > "Devices states are compatible with the current Power Resource states. In > other words, all devices are in the D3 state when the system state is S4." > > https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/07_Power_and_Performance_Mgmt/oem-supplied-system-level-control-methods.html Hi, I'd like to revive this thread and support this description from the ACPI spec. In ACPI 7.4.2.5, it states: "All devices are in the D3 state when the system state is S4," and in ACPI 7.4.2.6, it says: "The S5 state is similar to the S4 state except that OSPM does not save any context." I believe this implies that devices should also be in D3 when the system is in S5. > > > > > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=219036 > > > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > > > > --- > > > > drivers/pci/pci-driver.c | 8 ++++++++ > > > > 1 file changed, 8 insertions(+) > > > > > > > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > > > > index af2996d0d17f..4c6f66f3eb54 100644 > > > > --- a/drivers/pci/pci-driver.c > > > > +++ b/drivers/pci/pci-driver.c > > > > @@ -510,6 +510,14 @@ static void pci_device_shutdown(struct device *dev) > > > > if (drv && drv->shutdown) > > > > drv->shutdown(pci_dev); > > > > + /* > > > > + * If driver already changed device's power state, it can mean the > > > > + * wakeup setting is in place, or a workaround is used. > > > > Hence keep it > > > > + * as is. > > > > + */ > > > > + if (!kexec_in_progress && pci_dev->current_state == PCI_D0) > > > > + pci_prepare_to_sleep(pci_dev); > > > > + > > > > /* > > > > * If this is a kexec reboot, turn off Bus Master bit on the > > > > * device to tell it to not continue to do DMA. Don't touch > > > > -- > > > > 2.43.0 > > > > > > >
