Re: [PATCH RESEND 1/1] PCI: Add ATS-disable quirk for AMD Radeon R7 GPUs

From: Bjorn Helgaas
Date: Thu Apr 11 2019 - 09:59:08 EST


[+cc Alex, Suravee, Thomas, Felix, Christian]

On Mon, Apr 08, 2019 at 01:37:25PM +0300, Nikolai Kostrigin wrote:
> ATS is broken on this hardware (at least for Stoney Ridge
> based laptop) and causes IOMMU stalls and
> system failure. Disable ATS on these devices to make them
> usable again with IOMMU enabled
> Thanks to Joerg Roedel <jroedel@xxxxxxx> for help.
>
> https://bugzilla.kernel.org/show_bug.cgi?id=194521
>
> Signed-off-by: Nikolai Kostrigin <nickel@xxxxxxxxxxxx>

I applied this to pci/virtualization for v5.2 with Joerg's ack, a stable
tag, and a note about Alex's suspicion that this may be system-specific and
may also affect other devices.

> ---
> drivers/pci/quirks.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 4700d24e5d55..abb2532e16bf 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -4876,6 +4876,7 @@ static void quirk_no_ats(struct pci_dev *pdev)
>
> /* AMD Stoney platform GPU */
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x98e4, quirk_no_ats);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x6900, quirk_no_ats);
> #endif /* CONFIG_PCI_ATS */
>
> /* Freescale PCIe doesn't support MSI in RC mode */
> --
> 2.21.0
>