From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751445AbeFEBXu (ORCPT ); Mon, 4 Jun 2018 21:23:50 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52180 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbeFEBXt (ORCPT ); Mon, 4 Jun 2018 21:23:49 -0400 Subject: Re: [PATCH v8 2/2] iommu/amd: Add basic debugfs infrastructure for AMD IOMMU To: Greg KH , Gary R Hook Cc: iommu@lists.linux-foundation.org, joro@8bytes.org, linux-kernel@vger.kernel.org References: <152761784341.2654.8609366076331539902.stgit@sosgrh1.amd.com> <152761820371.2654.4551405686504157036.stgit@sosgrh1.amd.com> <20180529183917.GA10618@kroah.com> From: Randy Dunlap Message-ID: <9713a0b2-1450-7783-712f-ba27f8a09b2b@infradead.org> Date: Mon, 4 Jun 2018 18:23:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180529183917.GA10618@kroah.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/29/2018 11:39 AM, Greg KH wrote: > On Tue, May 29, 2018 at 01:23:23PM -0500, Gary R Hook wrote: >> Implement a skeleton framework for debugfs support in the >> AMD IOMMU. Add a hidden boolean to Kconfig that is defined >> for the AMD IOMMU when general IOMMY DebugFS support is >> enabled. >> >> Signed-off-by: Gary R Hook >> --- >> drivers/iommu/Kconfig | 4 ++++ >> drivers/iommu/Makefile | 1 + >> drivers/iommu/amd_iommu_debugfs.c | 39 +++++++++++++++++++++++++++++++++++++ >> drivers/iommu/amd_iommu_init.c | 6 ++++-- >> drivers/iommu/amd_iommu_proto.h | 6 ++++++ >> drivers/iommu/amd_iommu_types.h | 5 +++++ >> 6 files changed, 59 insertions(+), 2 deletions(-) >> create mode 100644 drivers/iommu/amd_iommu_debugfs.c >> >> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig >> index f9af25ac409f..ec223f6f4ad4 100644 >> --- a/drivers/iommu/Kconfig >> +++ b/drivers/iommu/Kconfig >> @@ -137,6 +137,10 @@ config AMD_IOMMU >> your BIOS for an option to enable it or if you have an IVRS ACPI >> table. >> >> +config AMD_IOMMU_DEBUGFS >> + def_bool y > > Why default y? Can you not boot a box without this? If not, it should > not be Y. > >> + depends on AMD_IOMMU && IOMMU_DEBUGFS >> + >> config AMD_IOMMU_V2 >> tristate "AMD IOMMU Version 2 driver" >> depends on AMD_IOMMU Gary, By far, most driver-debugfs additions are optional and include a user Kconfig prompt so that user's can choose whether to enable it or not. I suggest that the way forward is to fix Greg's debugfs_() api comments and to add a prompt string to AMD_IOMMU_DEBUGFS. -- ~Randy