[PATCH 5.6 047/106] PCI: Move Apex Edge TPU class quirk to fix BAR assignment

From: Greg Kroah-Hartman
Date: Fri May 01 2020 - 09:47:43 EST


From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

commit 0a8f41023e8a3c100b3dc458ed2da651bf961ead upstream.

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

f390d08d8b87 ("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@xxxxxxxxxxxxxx
Fixes: f390d08d8b87 ("staging: gasket: apex: fixup undefined PCI class")
Reported-by: LuÃs Mendes <luis.p.mendes@xxxxxxxxx>
Debugged-by: LuÃs Mendes <luis.p.mendes@xxxxxxxxx>
Tested-by: Luis Mendes <luis.p.mendes@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Todd Poynor <toddpoynor@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/pci/quirks.c | 7 +++++++
drivers/staging/gasket/apex_driver.c | 7 -------
2 files changed, 7 insertions(+), 7 deletions(-)

--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5567,3 +5567,10 @@ static void pci_fixup_no_d0_pme(struct p
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);
--- a/drivers/staging/gasket/apex_driver.c
+++ b/drivers/staging/gasket/apex_driver.c
@@ -570,13 +570,6 @@ static const struct pci_device_id apex_p
{ 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)
{