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Date: Sun, 17 Oct 2010 03:19:53 -0200
From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Sitsofe Wheeler <sitsofe@yahoo.com>, Matthew Garrett <mjg59@srcf.ucam.org>,
        Len Brown <lenb@kernel.org>, Zhang Rui <rui.zhang@intel.com>,
        David Zeuthen <davidz@redhat.com>,
        Richard Hughes <richard@hughsie.com>, linux-acpi@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ACPI / Battery: Return -ENODATA for unknown values in
 get_property() (was: Re: Returning ACPI_BATTERY ...)
Message-ID: <20101017051953.GA3430@khazad-dum.debian.net>
References: <20101016141321.GA11054@sucs.org>
 <201010170105.33274.rjw@sisk.pl>
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On Sun, 17 Oct 2010, Rafael J. Wysocki wrote:
> In fact, the driver is supposed to return -ENODATA in that case, which will
> result in the read from /sys/class/power_supply/BAT0/current_now fail (I guess
> upower should be able to cope with that).

ENODATA?  Shouldn't it be ENXIO?  There is no non-blocking data stream
involved in a sysfs attribute.

Of course, the RIGHT thing would be to not expose in sysfs attributes
that are unsupported by the firmware/hardware in the first place, but
that's easier said than done.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh