From: Joerg Roedel Subject: Re: [PATCH v8 13/13] iommu/amd: Disable iommu only if amd_iommu=off is specified Date: Thu, 27 Jul 2017 17:58:52 +0200 Message-ID: <20170727155852.GQ3610@suse.de> References: <1500627551-12930-1-git-send-email-bhe@redhat.com> <1500627551-12930-14-git-send-email-bhe@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1500627551-12930-14-git-send-email-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Baoquan He Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, root , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Fri, Jul 21, 2017 at 04:59:11PM +0800, Baoquan He wrote: > From: root You probaly need to reset the author on this one. > > It's ok to disable iommu in normal kernel. While there's no need > to disable it in kdump kernel after the on-flight dma issue has > heen fixed. > > Signed-off-by: Baoquan He > --- > drivers/iommu/amd_iommu_init.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c > index 8b4bac978062..880f693c809b 100644 > --- a/drivers/iommu/amd_iommu_init.c > +++ b/drivers/iommu/amd_iommu_init.c > @@ -2494,7 +2494,8 @@ static int __init early_amd_iommu_init(void) > goto out; > > /* Disable any previously enabled IOMMUs */ > - disable_iommus(); > + if (amd_iommu_disabled) > + disable_iommus(); > > if (amd_iommu_irq_remap) > amd_iommu_irq_remap = check_ioapic_information(); > -- > 2.5.5