Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752072AbdDHHk7 (ORCPT ); Sat, 8 Apr 2017 03:40:59 -0400 Received: from mailout1.hostsharing.net ([83.223.95.204]:39373 "EHLO mailout1.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751409AbdDHHkt (ORCPT ); Sat, 8 Apr 2017 03:40:49 -0400 Date: Sat, 8 Apr 2017 09:41:07 +0200 From: Lukas Wunner To: Joerg Roedel Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Daniel Drake , Alexander Deucher , Samuel Sieb , David Woodhouse , Joerg Roedel , Paul Menzel Subject: Re: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs Message-ID: <20170408074107.GA3585@wunner.de> References: <1491575538-22694-1-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1491575538-22694-1-git-send-email-joro@8bytes.org> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1978 Lines: 61 On Fri, Apr 07, 2017 at 04:32:18PM +0200, Joerg Roedel wrote: > From: Joerg Roedel > > 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. AMD Stoney Ridge is an x86 CPU + GPU combo and this quirk pertains to the GPU, right? In that case the quirk should go to arch/x86. Paul Menzel (+cc) has just complained on linux-pci@ that final fixups are taking half a second, and I think that could be reduced if more efforts were spent to move arch-specific quirks out of the catch-all in drivers/pci/quirks.c. Thanks, Lukas > > 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. > > Fixes: b1516a14657a ('iommu/amd: Implement flush queue') > Signed-off-by: Joerg Roedel > --- > drivers/pci/quirks.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 6736836..7cbe316 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -4634,3 +4634,22 @@ static void quirk_no_aersid(struct pci_dev *pdev) > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2031, quirk_no_aersid); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2032, quirk_no_aersid); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2033, quirk_no_aersid); > + > +#ifdef CONFIG_PCI_ATS > +/* > + * Some devices have a broken ATS implementation causing IOMMU stalls. > + * Don't use ATS for those devices. > + */ > +static void quirk_disable_ats(struct pci_dev *pdev) > +{ > + /* > + * Set pdev->ats_cap = 0 to make pci_enable_ats() bail out > + * early. > + */ > + dev_info(&pdev->dev, "QUIRK: Disabling ATS"); > + pdev->ats_cap = 0; > +} > + > +/* AMD Stoney platform GPU */ > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x98e4, quirk_disable_ats); > +#endif /* CONFIG_PCI_ATS */ > -- > 1.9.1 >