Hi, On Sun, Jul 02, 2017 at 03:59:48PM -0500, Bjorn Helgaas wrote: > Neither soft poweroff (transition to ACPI power state S5) nor > suspend-to-RAM (transition to state S3) works on the Macbook Pro 11,4 and > 11,5. > > The problem is related to the [mem 0x7fa00000-0x7fbfffff] space. When we > use that space, e.g., by assigning it to the 00:1c.0 Root Port, the ACPI > Power Management 1 Control Register (PM1_CNT) at [io 0x1804] doesn't work > anymore. > > Linux does a soft poweroff (transition to S5) by writing to PM1_CNT. The > theory about why this doesn't work is: > > - The write to PM1_CNT causes an SMI > - The BIOS SMI handler depends on something in > [mem 0x7fa00000-0x7fbfffff] > - When Linux assigns [mem 0x7fa00000-0x7fbfffff] to the 00:1c.0 Port, it > covers up whatever the SMI handler uses, so the SMI handler no longer > works correctly > > Reserve the [mem 0x7fa00000-0x7fbfffff] space so we don't assign it to > anything. > > This is voodoo programming, since we don't know what the real conflict is, > but we've failed to find the root cause. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=103211 > Tested-by: thejoe@xxxxxxxxx > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx> > Cc: Lukas Wunner <lukas@xxxxxxxxx> > Cc: Chen Yu <yu.c.chen@xxxxxxxxx> > > diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c > index 6d52b94f4bb9..20fa7c84109d 100644 > --- a/arch/x86/pci/fixup.c > +++ b/arch/x86/pci/fixup.c > @@ -571,3 +571,35 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, pci_invalid_bar); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_invalid_bar); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_invalid_bar); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar); > + > +/* > + * Apple MacBook Pro: Avoid [mem 0x7fa00000-0x7fbfffff] > + * > + * Using the [mem 0x7fa00000-0x7fbfffff] region, e.g., by assigning it to > + * the 00:1c.0 Root Port, causes a conflict with [io 0x1804], which is used > + * for soft poweroff and suspend-to-RAM. > + * > + * As far as we know, this is related to the address space, not to the Root > + * Port itself. Attaching the quirk to the Root Port is a convenience, but > + * it could probably also be a standalone DMI quirk. > + * > + * https://bugzilla.kernel.org/show_bug.cgi?id=103211 > + */ > +static void quirk_apple_mbp_poweroff(struct pci_dev *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct resource *res; > + > + if ((!dmi_match(DMI_PRODUCT_NAME, "MacBookPro11,4") && > + !dmi_match(DMI_PRODUCT_NAME, "MacBookPro11,5")) || > + pdev->bus->number != 0 || pdev->devfn != PCI_DEVFN(0x1c, 0)) > + return; > + Not sure why we need to also the bus number of devfn, as there is only one PCI bridge that would match 0x8c10? according to https://bugzilla.kernel.org/attachment.cgi?id=210611 am I missing something? thanks, Yu > + res = request_mem_region(0x7fa00000, 0x200000, > + "MacBook Pro poweroff workaround"); > + if (res) > + dev_info(dev, "claimed %s %pR\n", res->name, res); > + else > + dev_info(dev, "can't work around MacBook Pro poweroff issue\n"); > +} > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x8c10, quirk_apple_mbp_poweroff);
