Commit 9b44b0b0 authored Jul 11, 2017 by Joerg Roedel Committed by Bjorn Helgaas Jul 31, 2017

PCI: Mark AMD Stoney GPU ATS as broken

ATS is broken on this hardware and causes IOMMU stalls and system failure.
Disable ATS on these devices to make them usable again with IOMMU enabled.

Note that the commit in the Fixes tag is not buggy; it just uncovers the
problem in the hardware by increasing the ATS flush rate.

Link: https://lists.linuxfoundation.org/pipermail/iommu/2017-March/020836.html
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1409201


Fixes: b1516a14 ("iommu/amd: Implement flush queue")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>

parent 16f73eb0

drivers/pci/quirks.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -4681,3 +4681,18 @@ static void quirk_intel_no_flr(struct pci_dev *dev)
		}
		DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr);
		DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr);

		#ifdef CONFIG_PCI_ATS
		/*
		* Some devices have a broken ATS implementation causing IOMMU stalls.
		* Don't use ATS for those devices.
		*/
		static void quirk_no_ats(struct pci_dev *pdev)
		{
		dev_info(&pdev->dev, "disabling ATS (broken on this device)\n");
		pdev->ats_cap = 0;
		}

		/* AMD Stoney platform GPU */
		DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x98e4, quirk_no_ats);
		#endif /* CONFIG_PCI_ATS */

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