Hi, On Fri, Feb 11, 2022 at 04:06:20PM -0600, Limonciello, Mario wrote: > On 2/11/2022 15:35, Bjorn Helgaas wrote: > > On Fri, Feb 11, 2022 at 01:32:41PM -0600, Mario Limonciello wrote: > > > `pci_bridge_d3_possible` currently checks explicitly for a Thunderbolt > > > controller to indicate that D3 is possible. As this is used solely > > > for older Apple systems, move it into a quirk that enumerates across > > > all Intel TBT controllers. > > > > > > Suggested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> > > > --- > > > drivers/pci/pci.c | 12 +++++----- > > > drivers/pci/quirks.c | 53 ++++++++++++++++++++++++++++++++++++++++++++ > > > 2 files changed, 60 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index 9ecce435fb3f..5002e214c9a6 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -1064,7 +1064,13 @@ static inline bool platform_pci_bridge_d3(struct pci_dev *dev) > > > if (pci_use_mid_pm()) > > > return false; > > > - return acpi_pci_bridge_d3(dev); > > > + if (acpi_pci_bridge_d3(dev)) > > > + return true; > > > + > > > + if (device_property_read_bool(&dev->dev, "HotPlugSupportInD3")) > > > + return true; > > > > Why do we need this? acpi_pci_bridge_d3() already looks for > > "HotPlugSupportInD3". > > The Apple machines don't have ACPI companion devices that specify this > property. > > I guess this probes a different question; can `device_property_read_bool` be > used in `acpi_pci_bridge_d3` instead of: > > if (acpi_dev_get_property(adev, "HotPlugSupportInD3", > ACPI_TYPE_INTEGER, &obj) < 0) > return false; > > return obj->integer.value == 1; > > If so, then yeah this can probably be simplified. Unfortunately the code in acpi_pci_bridge_d3() expects the device to have an ACPI_COMPANION() which may not be the case with software nodes. > > > > > + return false; > > > } > > > /** > > > @@ -2954,10 +2960,6 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge) > > > if (pci_bridge_d3_force) > > > return true; > > > - /* Even the oldest 2010 Thunderbolt controller supports D3. */ > > > - if (bridge->is_thunderbolt) > > > - return true; > > > - > > > /* Platform might know better if the bridge supports D3 */ > > > if (platform_pci_bridge_d3(bridge)) > > > return true; > > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > > > index 6d3c88edde00..aaf098ca7d54 100644 > > > --- a/drivers/pci/quirks.c > > > +++ b/drivers/pci/quirks.c > > > @@ -3756,6 +3756,59 @@ DECLARE_PCI_FIXUP_SUSPEND_LATE(PCI_VENDOR_ID_INTEL, > > > quirk_apple_poweroff_thunderbolt); > > > #endif > > > +/* Apple machines as old as 2010 can do D3 with Thunderbolt controllers, but don't specify > > > + * it in the ACPI tables > > > > Wrap to fit in 80 columns like the rest of the file. Also use the: > > > > /* > > * comment ... > > */ > > > > style if it's more than one line. > > > > I don't think "as old as 2010" is helpful here -- I assume 2010 is > > there because there *were* no Thunderbolt controllers before 2010, but > > the code doesn't check any dates, so we basically assume all Apple > > machines of any age with the listed controllers can do this. > > The old comment was saying that, which is where I got it from. Yeah, I'll > update it. > > > > > > + */ > > > +static void quirk_apple_d3_thunderbolt(struct pci_dev *dev) > > > +{ > > > + struct property_entry properties[] = { > > > + PROPERTY_ENTRY_BOOL("HotPlugSupportInD3"), > > > + {}, > > > + }; > > > + > > > + if (!x86_apple_machine) > > > + return; > > > > The current code doesn't check x86_apple_machine, so this needs some > > justification. How do I know this works the same as before? > > Mika and Lucas were saying the only reason for this codepath was Apple > machines in the first place, which is where this idea came from. Yes, that's the reason. Nobody else is going to need this except Apple machines with Intel Thunderbolt controller. > Something specifically relevant is that the Apple machines use a SW > connection manager, whereas everyone else up until USB4 devices use a > firmware based connection manager with varying behaviors on generation > (ICM). Yup. > > > + > > > + if (device_create_managed_software_node(&dev->dev, properties, NULL)) > > > + pci_warn(dev, "could not add HotPlugSupportInD3 property"); > > > +} > > > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_LIGHT_RIDGE, > > > + quirk_apple_d3_thunderbolt); > > > > The current code assumes *all* Thunderbolt controllers support D3, so > > it would assume a controller released next year would support D3, but > > this code would assume the opposite. Are we supposed to add > > everything to this list, or do newer machines supply > > HotPlugSupportInD3, or ...? > > This quirk is intended specifically for Apple, which has stopped making > Intel machines with Intel TBT controllers. > > So I don't believe the list should be growing any more, if anything it might > need to shrink if I got too many models that weren't actually in Apple > products. Lucas probably needs to confirm that. Yes correct it won't be growing more.