Commit 0a8f4102 authored Apr 09, 2020 by Bjorn Helgaas

PCI: Move Apex Edge TPU class quirk to fix BAR assignment

Some Google Apex Edge TPU devices have a class code of 0
(PCI_CLASS_NOT_DEFINED).  This prevents the PCI core from assigning
resources for the Apex BARs because __dev_sort_resources() ignores
classless devices, host bridges, and IOAPICs.

On x86, firmware typically assigns those resources, so this was not a
problem.  But on some architectures, firmware does *not* assign BARs, and
since the PCI core didn't do it either, the Apex device didn't work
correctly:

  apex 0000:01:00.0: can't enable device: BAR 0 [mem 0x00000000-0x00003fff 64bit pref] not claimed
  apex 0000:01:00.0: error enabling PCI device

f390d08d ("staging: gasket: apex: fixup undefined PCI class") added a
quirk to fix the class code, but it was in the apex driver, and if the
driver was built as a module, it was too late to help.

Move the quirk to the PCI core, where it will always run early enough that
the PCI core will assign resources if necessary.

Link: https://lore.kernel.org/r/CAEzXK1r0Er039iERnc2KJ4jn7ySNUOG9H=Ha8TD8XroVqiZjgg@mail.gmail.com


Fixes: f390d08d ("staging: gasket: apex: fixup undefined PCI class")
Reported-by: Luís Mendes <luis.p.mendes@gmail.com>
Debugged-by: Luís Mendes <luis.p.mendes@gmail.com>
Tested-by: Luis Mendes <luis.p.mendes@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Todd Poynor <toddpoynor@google.com>

parent 8f3d9f35

drivers/pci/quirks.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -5567,3 +5567,10 @@ static void pci_fixup_no_d0_pme(struct pci_dev *dev)
		dev->pme_support &= ~(PCI_PM_CAP_PME_D0 >> PCI_PM_CAP_PME_SHIFT);
		}
		DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASMEDIA, 0x2142, pci_fixup_no_d0_pme);

		static void apex_pci_fixup_class(struct pci_dev *pdev)
		{
		pdev->class = (PCI_CLASS_SYSTEM_OTHER << 8) \| pdev->class;
		}
		DECLARE_PCI_FIXUP_CLASS_HEADER(0x1ac1, 0x089a,
		PCI_CLASS_NOT_DEFINED, 8, apex_pci_fixup_class);

drivers/staging/gasket/apex_driver.c

+0 −7

Original line number	Diff line number	Diff line
		@@ -570,13 +570,6 @@ static const struct pci_device_id apex_pci_ids[] = {
		{ PCI_DEVICE(APEX_PCI_VENDOR_ID, APEX_PCI_DEVICE_ID) }, { 0 }
		};

		static void apex_pci_fixup_class(struct pci_dev *pdev)
		{
		pdev->class = (PCI_CLASS_SYSTEM_OTHER << 8) \| pdev->class;
		}
		DECLARE_PCI_FIXUP_CLASS_HEADER(APEX_PCI_VENDOR_ID, APEX_PCI_DEVICE_ID,
		PCI_CLASS_NOT_DEFINED, 8, apex_pci_fixup_class);

		static int apex_pci_probe(struct pci_dev *pci_dev,
		const struct pci_device_id *id)
		{

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