Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755682Ab3FGKa6 (ORCPT ); Fri, 7 Jun 2013 06:30:58 -0400 Received: from mail-bk0-f49.google.com ([209.85.214.49]:53454 "EHLO mail-bk0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753225Ab3FGKa4 (ORCPT ); Fri, 7 Jun 2013 06:30:56 -0400 From: Tomasz Figa To: Mark Brown Cc: Doug Anderson , Chris Ball , Olof Johansson , Andrew Bresticker , Alim Akhtar , Abhilash Kesavan , Jaehoon Chung , Seungwon Jeon , Grant Likely , Rob Herring , Rob Landley , Will Newton , devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, lgirdwood@gmail.com Subject: Re: [PATCH 1/2] mmc: dw_mmc: Handle late vmmc regulator with EPROBE_DEFER Date: Fri, 07 Jun 2013 12:30:52 +0200 Message-ID: <1841650.N6Drbs67FD@flatron> User-Agent: KMail/4.10.4 (Linux/3.9.4-gentoo; KDE/4.10.4; x86_64; ; ) In-Reply-To: <20130607102404.GO31367@sirena.org.uk> References: <1370580406-10254-1-git-send-email-dianders@chromium.org> <1664692.GUOAAQ3FLn@flatron> <20130607102404.GO31367@sirena.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 39 On Friday 07 of June 2013 11:24:04 Mark Brown wrote: > On Fri, Jun 07, 2013 at 12:19:58PM +0200, Tomasz Figa wrote: > > On Thursday 06 of June 2013 21:46:45 Doug Anderson wrote: > > > dw_mmc is probed. This regulator is optional, though a warning will > > > be printed if it's missing. The fact that the regulator is optional > > > means that (at the moment) it's not possible to use a regulator that > > > probes _after_ dw_mmc. > > > > > > Fix this limitation by adding the ability to make vmmc required. If > > > a > > > vmmc-supply is specified in the device tree we'll assume that vmmc > > > is > > > required. > > > > This interesting case makes me think that regulator core should > > differentiate between regulator lookup failure due to no lookup > > specified and due to the regulator specified in lookup being > > unavailable, returning appropriate (different) error codes. > > It does exactly that in so far as it can - you get -ENODEV if there's > definitely no supply and -EPROBE_DEFER otherwise. Oh, right, thanks. I somehow felt that it should be doing this already, but I was looking at 3.9 on Free Electron's LXR. It does so since commit 1e4b545cdd regulator: core: return err value for regulator_get if there is no DT binding so I think this patch should be reworked to check the returned error code instead. Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/