Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754407AbcDYKQN (ORCPT ); Mon, 25 Apr 2016 06:16:13 -0400 Received: from mail.kernel.org ([198.145.29.136]:36659 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752426AbcDYKQL (ORCPT ); Mon, 25 Apr 2016 06:16:11 -0400 Date: Mon, 25 Apr 2016 11:15:29 +0100 (BST) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-X260 To: Mark Rutland cc: Stefano Stabellini , catalin.marinas@arm.com, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, julien.grall@arm.com, david.vrabel@citrix.com, xen-devel@lists.xen.org, devicetree@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, shannon.zhao@linaro.org, peter.huangpeng@huawei.com Subject: Re: [PATCH v11 12/17] ARM64: ACPI: Check if it runs on Xen to enable or disable ACPI In-Reply-To: <20160422103250.GC10606@leverpostej> Message-ID: References: <1460030614-16112-1-git-send-email-zhaoshenglong@huawei.com> <1460030614-16112-13-git-send-email-zhaoshenglong@huawei.com> <20160422103250.GC10606@leverpostej> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2964 Lines: 91 On Fri, 22 Apr 2016, Mark Rutland wrote: > On Wed, Apr 20, 2016 at 10:34:41AM +0100, Stefano Stabellini wrote: > > Hello Mark, > > > > do you think that this patch addresses your previous comments > > (http://marc.info/?l=devicetree&m=145926913008544&w=2) appropriately? > > > > Thanks, > > > > Stefano > > > > On Thu, 7 Apr 2016, Shannon Zhao wrote: > > > From: Shannon Zhao > > > > > > When it's a Xen domain0 booting with ACPI, it will supply a /chosen and > > > a /hypervisor node in DT. So check if it needs to enable ACPI. > > > > > > Signed-off-by: Shannon Zhao > > > Reviewed-by: Stefano Stabellini > > > Acked-by: Hanjun Guo > > > --- > > > arch/arm64/kernel/acpi.c | 14 ++++++++++---- > > > 1 file changed, 10 insertions(+), 4 deletions(-) > > > > > > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > > > index d1ce8e2..57ee317 100644 > > > --- a/arch/arm64/kernel/acpi.c > > > +++ b/arch/arm64/kernel/acpi.c > > > @@ -67,10 +67,15 @@ static int __init dt_scan_depth1_nodes(unsigned long node, > > > { > > > /* > > > * Return 1 as soon as we encounter a node at depth 1 that is > > > - * not the /chosen node. > > > + * not the /chosen node, or /hypervisor node with compatible > > > + * string "xen,xen". > > > */ > > > - if (depth == 1 && (strcmp(uname, "chosen") != 0)) > > > - return 1; > > > + if (depth == 1 && (strcmp(uname, "chosen") != 0)) { > > > + if (strcmp(uname, "hypervisor") != 0 || > > > + !of_flat_dt_is_compatible(node, "xen,xen")) > > > + return 1; > > > + } > > > + > > > return 0; > > > } > > Is the duplicate node checking logic I mentioned in that review gone? > i.e. do we not need an is_xen_node() helper? Given the simplicity of just calling of_flat_dt_is_compatible(node, "xen,xen"), I think we can do without the helper. Also the function in the previous patch also checks for the Xen version which is not needed here. > Additionally, IMO, this would be easier to follow without the nested > conditionals, e.g. > > static int __init dt_scan_depth1_nodes(unsigned long node, > const char *uname, int depth, > void *data) > { > /* > * Ignore anything not directly under the root node; we'll > * catch its parent instead. > */ > if (depth != 1) > return 0; > > if (strcmp(uname, "chosen") == 0) > return 0; > > if (strcmp(uname, "hypervisor") == 0 && > of_flat_dt_is_compatible(node, "xen,xen")) > return 0; > > /* > * This node at depth 1 is neither a chosen node nor a xen node, > * which we do not expect. > */ > return 1; > } > > Otherwise, this looks fine to me. FWIW, either way: > > Acked-by: Mark Rutland That is easier to read. For simplicity, I'll submit a patch with you as author, on top of the existing, to make this change. I'll use your Signed-off-by, if that's OK.