From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH V4] IOMMU, AMD Family15h Model10-1Fh erratum 746 Workaround Date: Thu, 24 Jan 2013 21:00:34 +0100 Message-ID: <20130124200034.GM13463@pd.tnic> References: <1359055073-29732-1-git-send-email-suravee.suthikulpanit@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <1359055073-29732-1-git-send-email-suravee.suthikulpanit@amd.com> Sender: linux-kernel-owner@vger.kernel.org To: suravee.suthikulpanit@amd.com Cc: iommu@lists.linux-foundation.org, joro@8bytes.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org On Thu, Jan 24, 2013 at 01:17:53PM -0600, suravee.suthikulpanit@amd.com wrote: > From: Suravee Suthikulpanit > > The IOMMU may stop processing page translations due to a perceived lack > of credits for writing upstream peripheral page service request (PPR) > or event logs. If the L2B miscellaneous clock gating feature is enabled > the IOMMU does not properly register credits after the log request has > completed, leading to a potential system hang. > > BIOSes are supposed to disable L2B micellaneous clock gating by setting > L2_L2B_CK_GATE_CONTROL[CKGateL2BMiscDisable](D0F2xF4_x90[2]) = 1b. This > patch corrects that for those which do not enable this workaround. > > Signed-off-by: Suravee Suthikulpanit Acked-by: Borislav Petkov Thanks for the good work. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --