From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752383AbcKGIf5 (ORCPT ); Mon, 7 Nov 2016 03:35:57 -0500 Received: from ozlabs.org ([103.22.144.67]:57399 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750898AbcKGIfb (ORCPT ); Mon, 7 Nov 2016 03:35:31 -0500 From: Michael Ellerman To: Paolo Bonzini , alex.williamson@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, aik@ozlabs.ru, gwshan@linux.vnet.ibm.com Subject: Re: [PATCH] vfio: Fix build break when SPAPR_TCE_IOMMU=n In-Reply-To: <81900126-f1aa-b480-c2fa-f0fa04d625c1@redhat.com> References: <1478238521-32203-1-git-send-email-mpe@ellerman.id.au> <81900126-f1aa-b480-c2fa-f0fa04d625c1@redhat.com> User-Agent: Notmuch/0.21 (https://notmuchmail.org) Date: Mon, 07 Nov 2016 19:34:42 +1100 Message-ID: <87zilblmcd.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paolo Bonzini writes: > On 04/11/2016 06:48, Michael Ellerman wrote: >> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig >> index da6e2ce77495..6b51a4ebed8a 100644 >> --- a/drivers/vfio/Kconfig >> +++ b/drivers/vfio/Kconfig >> @@ -6,12 +6,12 @@ config VFIO_IOMMU_TYPE1 >> config VFIO_IOMMU_SPAPR_TCE >> tristate >> depends on VFIO && SPAPR_TCE_IOMMU >> - default n >> + default VFIO > > No need to depend on VFIO since you already have it in "default". True, I can take that out. > (I assume you cannot use "default y" because "depends on" doesn't downgrade > "y" to "m" when VFIO is a module. Correct. > A shorthand is > > def_tristate VFIO && SPAPR_TCE_IOMMU Yep. My experience though is that a lot of folks don't really know what that means. So I prefer to spell it out with an explicit type, depends and default. But I'll respin it that way if Alex prefers the shorter style. cheers