Commit 675734ba authored Mar 21, 2017 by Bjorn Helgaas

PCI: Enable ECRC only if device supports it

John reported that an Intel QuickAssist crypto accelerator didn't work in a
Dell PowerEdge R730. The problem seems to be that we enabled ECRC when the
device doesn't support it:

85:00.0 Co-processor [0b40]: Intel Corporation DH895XCC Series QAT [8086:0435]
Capabilities: [100 v1] Advanced Error Reporting
AERCap: First Error Pointer: 00, GenCap- CGenEn+ ChkCap- ChkEn+

1302fcf0 ("PCI: Configure *all* devices, not just hot-added ones")
exposed the problem because it applies settings from the _HPX method to all
devices, not just hot-added ones. The R730 supplies an _HPX method that
allows the kernel to enable ECRC.

Only enable ECRC if the device advertises support for it.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1571798

Fixes: 1302fcf0 ("PCI: Configure *all* devices, not just hot-added ones")
Reported-by: John Mazzie <john_mazzie@dell.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent 56c1af46

drivers/pci/probe.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1704,6 +1704,11 @@ static void program_hpp_type2(struct pci_dev dev, struct hpp_type2 hpp)
		/* Initialize Advanced Error Capabilities and Control Register */
		pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
		reg32 = (reg32 & hpp->adv_err_cap_and) \| hpp->adv_err_cap_or;
		/* Don't enable ECRC generation or checking if unsupported */
		if (!(reg32 & PCI_ERR_CAP_ECRC_GENC))
		reg32 &= ~PCI_ERR_CAP_ECRC_GENE;
		if (!(reg32 & PCI_ERR_CAP_ECRC_CHKC))
		reg32 &= ~PCI_ERR_CAP_ECRC_CHKE;
		pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);

		/*

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