From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH] ACPI/device_sysfs: Add sysfs support for _HRV hardware revision Date: Wed, 27 Apr 2016 23:19:15 +0200 Message-ID: <12004194.mLBeKcyjTJ@vostro.rjw.lan> References: <1460558894-11971-1-git-send-email-betty.dall@hpe.com> <3691881.pb3S7Il1cr@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from cloudserver094114.home.net.pl ([79.96.170.134]:58000 "HELO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753085AbcD0VQP (ORCPT ); Wed, 27 Apr 2016 17:16:15 -0400 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Dall, Betty" Cc: "lenb@kernel.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" On Wednesday, April 27, 2016 04:15:30 PM Dall, Betty wrote: > On 04/26/2016 02:33 PM, Rafael J. Wysocki wrote: > > On Wednesday, April 13, 2016 08:48:14 AM Betty Dall wrote: > >> The ACPI _HRV object on the device is used to supply Linux with > >> the device's hardware revision. This is an optional object. Add > >> sysfs support for the _HRV object if it exists on the device. > >> > >> Signed-off-by: Betty Dall > > > > The patch itself looks OK to me, but why exactly do we need that thing in sysfs? > > > > Thanks, > > Rafael > > > Hi Rafael, > > I am working on a platform where non-PCI hardware is changing quickly > and users want to check what hardware version they are running on. For > example, someone checks out a lab system and wants to see if the device > is the latest version or if it needs to be updated - they could cat the > sysfs hrv file to find the version. It is most useful for non-PCI > devices because lspci can list the hardware version for PCI devices; PCI > devices in my testing don't supply _HRV. But, there is not an easy > solution for non-PCI devices to get the hardware revision from user > space with out this hrv sysfs patch. > > Originally, I added the sysfs hrv to my specific device driver. On > review, I thought it would a good improvement for all devices that have > an _HRV. OK Can you please add a motivation paragraph to the patch changelog then? Thanks, Rafael