Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753134AbbG2SWS (ORCPT ); Wed, 29 Jul 2015 14:22:18 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:36114 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbbG2SWP (ORCPT ); Wed, 29 Jul 2015 14:22:15 -0400 MIME-Version: 1.0 In-Reply-To: <20150729171613.GI11162@sirena.org.uk> References: <557c1962448393b2a8736f26bfa2a3a5ba4aeb7a.1438170519.git.hramrach@gmail.com> <20150729140046.GB11082@sirena.org.uk> <20150729171613.GI11162@sirena.org.uk> From: Michal Suchanek Date: Wed, 29 Jul 2015 20:21:34 +0200 Message-ID: Subject: Re: [RFC PATCH 2/2] dt: spi: s3c64xx: add compatible to controller-data To: Mark Brown Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , David Woodhouse , Brian Norris , Kukjin Kim , Krzysztof Kozlowski , Padmavathi Venna , Boris BREZILLON , devicetree , Linux Kernel Mailing List , MTD Maling List , "linux-arm-kernel@lists.infradead.org" , linux-samsung-soc , linux-spi Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2225 Lines: 49 On 29 July 2015 at 19:16, Mark Brown wrote: > On Wed, Jul 29, 2015 at 06:19:24PM +0200, Michal Suchanek wrote: >> On 29 July 2015 at 16:00, Mark Brown wrote: > >> > I can't tell from this commit message what the issue you're trying to >> > fix is, sorry. Nodes without compatible strings are entirely normal and >> > don't need compatible strings. It sounds like a bug in whatever other >> > driver is becoming confused. > >> The driver that gets confused is ofpart. > >> The two-line patch to allow it to just ignore controller-data has been >> rejected on the basis that s3c64xx should use a compatible string >> because ofpart monopolizes all nodes without compatible which are >> children of a mtd device. Devicetrees containing such nodes that are >> not partitions are presumably invalid and should be rejected when >> ofpart is compiled into the kernel. > > That seems like an extremely limited binding, the normal thing here > would be to create a specifically named node to contain the collection > of subnodes like many PMICs do for their regulators. As a fix I'd > suggest just silently ignoring nodes it can't understand, or printing a > warning if that's a serious issue. > >> >> + if (!of_get_property(data_np, "compatible", NULL) || >> >> + strcmp(of_get_property(data_np, "compatible", NULL), >> >> + "samsung,s3c-controller-data")) >> >> + dev_err(&spi->dev, "child node 'controller-data' does not have correct compatible\n"); > >> > This will break all existing users which is not acceptable for >> > mainline, we need to preserve compatibility with existing device trees. > >> It will not break anything. It will just spam dmesg. > > I'm confused - if all this change does is to spam dmesg then what's the > point? Presumably when your SPI NOR flash fails to probe this message will be just above and you will look into the binding doc and add the compatible. Thanks Michal -- 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/