From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sitsofe Wheeler Subject: Re: [PATCH] ACPI / Battery: Return -ENODATA for unknown values in get_property() Date: Thu, 21 Oct 2010 17:54:20 +0100 Message-ID: <20101021165420.GA8718@sucs.org> References: <20101016141321.GA11054@sucs.org> <20101017131016.GB13015@khazad-dum.debian.net> <20101017145025.GA32599@sucs.org> <201010172032.43206.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <201010172032.43206.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Henrique de Moraes Holschuh , Matthew Garrett , Len Brown , Zhang Rui , David Zeuthen , Richard Hughes , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-acpi@vger.kernel.org On Sun, Oct 17, 2010 at 08:32:42PM +0200, Rafael J. Wysocki wrote: > > Still, if user space has problems with failing reads from the sysfs > attributes, it may be better to simply put -1 in there. Patch is > appended, please test. This patch does what it says on the tin (returns -1 in sysfs on my EeePC 900). So: Tested-by: Sitsofe Wheeler It's a shame the previous changes didn't work as they stopped a buggy upower using the -1 value (and producing a nonsense rate like 8.4e-06) but it's not clear which part of the stack can't handle -ENODATA perhaps it is another part of the kernel? Richard, any chance of upower being changed to test for -1 before doing doing anything with current_now ( http://cgit.freedesktop.org/DeviceKit/upower/tree/src/linux/up-device-supply.c?id=5387183d53c16a987a0737c1bdec1b62edf3daa6#n561)? I guess there are a whole bunch of other attributes that could theoretically be -1 and shouldn't be used if they return it... -- Sitsofe | http://sucs.org/~sits/