From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753441AbcD0VSh (ORCPT ); Wed, 27 Apr 2016 17:18:37 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:53829 "HELO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752654AbcD0VSg (ORCPT ); Wed, 27 Apr 2016 17:18:36 -0400 From: "Rafael J. Wysocki" To: "Dall, Betty" Cc: "lenb@kernel.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] ACPI/device_sysfs: Add sysfs support for _HRV hardware revision Date: Wed, 27 Apr 2016 23:21:37 +0200 Message-ID: <1818106.auxzDWcdFV@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.5.0-rc1+; KDE/4.11.5; x86_64; ; ) In-Reply-To: References: <1460558894-11971-1-git-send-email-betty.dall@hpe.com> <2388310.jGjaKS2NDe@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, April 27, 2016 04:19:45 PM Dall, Betty wrote: > On 04/26/2016 02:39 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 > >> --- > >> drivers/acpi/device_sysfs.c | 24 ++++++++++++++++++++++++ > >> 1 file changed, 24 insertions(+) > >> > >> diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c > >> index b9afb47..bf12dbe 100644 > >> --- a/drivers/acpi/device_sysfs.c > >> +++ b/drivers/acpi/device_sysfs.c > >> @@ -473,6 +473,21 @@ acpi_device_sun_show(struct device *dev, struct device_attribute *attr, > >> } > >> static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL); > >> > >> +static ssize_t > >> +acpi_device_hrv_show(struct device *dev, struct device_attribute *attr, > >> + char *buf) { > >> + struct acpi_device *acpi_dev = to_acpi_device(dev); > >> + acpi_status status; > >> + unsigned long long hrv; > >> + > >> + status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv); > >> + if (ACPI_FAILURE(status)) > >> + return -ENODEV; > > > > Actually, this should be -EIO I think. > > > > Thanks, > > Rafael > > Hi Rafael, > > I picked -ENODEV because the _SUN and _STA show functions use -ENODEV > for a return value when the acpi_evaluate_integer() fails. Which isn't the best choice. > I checked in the sysfs code what the return value is used for and any > negative value is treated the same, that is, the sysfs code is not > looking specifically for -EIO. But doesn't it pass the return value up the call chain? > Do you still want me to change it to -EIO? I may, depending on the answer to the question above. Thanks, Rafael