From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH] iommu/amd: Fix amd_iommu_detect() (does not fix any issues). Date: Mon, 26 Oct 2015 12:07:17 -0400 Message-ID: <20151026160717.GF5618@l.oracle.com> References: <1441059183-9023-1-git-send-email-j.glisse@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <1441059183-9023-1-git-send-email-j.glisse-Re5JQEeQqe8AvxtiuMwx3w@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: j.glisse-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Cc: =?iso-8859-1?B?Suly9G1l?= Glisse , Joerg Roedel , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Mon, Aug 31, 2015 at 06:13:03PM -0400, j.glisse-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote: > From: J=E9r=F4me Glisse > = > Fix amd_iommu_detect() to return positive value on success, like > intended, and not zero. This will not change anything in the end > as AMD IOMMU disable swiotlb and properly associate itself with Not sure how it disables SWIOTLB? The AMD Vi does not seem to change 'swiotlb'. While 'gart_iommu_init' does. Did you mean the AMD GART code? > devices even if detect() doesn't return a positive value. Returning positive will mean that the pci_iommu_alloc will stop processing _all_ other IOMMUs. While returning 0 will let it detect the other IOMMUs. Granted on an AMD machine there can be two 'IOMMU's - the GART and the AMD Vi. The detection is always to call gart_iommu_hole_init first, then amd_iommu_detect. I presume if there was one more type on AMD we would run into trouble. > = > Signed-off-by: J=E9r=F4me Glisse > Cc: Joerg Roedel > Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > --- > drivers/iommu/amd_iommu_init.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > = > diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_ini= t.c > index a24495e..360a451 100644 > --- a/drivers/iommu/amd_iommu_init.c > +++ b/drivers/iommu/amd_iommu_init.c > @@ -2198,7 +2198,7 @@ int __init amd_iommu_detect(void) > iommu_detected =3D 1; > x86_init.iommu.iommu_init =3D amd_iommu_init; > = > - return 0; > + return 1; > } > = > /***********************************************************************= ***** > -- = > 1.8.3.1 > = > _______________________________________________ > iommu mailing list > iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu