From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754749AbbIBQfS (ORCPT ); Wed, 2 Sep 2015 12:35:18 -0400 Received: from smtp5-g21.free.fr ([212.27.42.5]:52092 "EHLO smtp5-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751876AbbIBQfQ (ORCPT ); Wed, 2 Sep 2015 12:35:16 -0400 Date: Wed, 2 Sep 2015 18:35:06 +0200 From: Alban To: Philipp Zabel Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] reset: Fix of_reset_control_get() for consistent return values Message-ID: <20150902183506.5e7affdf@avionic-0020> In-Reply-To: <1441206592.3279.45.camel@pengutronix.de> References: <1441121311-31628-1-git-send-email-albeu@free.fr> <1441206592.3279.45.camel@pengutronix.de> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 02 Sep 2015 17:09:52 +0200 Philipp Zabel wrote: > Hi Alban, > > Am Dienstag, den 01.09.2015, 17:28 +0200 schrieb Alban Bedel: > > When of_reset_control_get() is called without connection ID it returns > > -ENOENT when the 'resets' property doesn't exists or is an empty entry. > > However when a connection ID is given it returns -EINVAL when the 'resets' > > property doesn't exists or the requested name can't be found. This is > > because the error code returned by of_property_match_string() is just > > passed down as an index to of_parse_phandle_with_args(), which then > > returns -EINVAL. > > Is that true? As far as I can see, since commit bd69f73f2c81 > ("of: Create function for counting number of phandles in a property") > it returns the (positive) number of entries if index is negative and the > 'resets' property exists and parses correctly (before it would return > -ENOENT). If there are parsing errors, it can also return -EINVAL. That's no really the case. If the property doesn't exists, or the requested index is out of range, of_parse_phandle_with_args() always return -ENOENT. This is important for optional properties. However if the index is negative it always return -EINVAL, independently of the property existence. And here it is what happen when of_property_match_string() fails, leading to this inconsistence. Alban