Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755472AbbHFLYL (ORCPT ); Thu, 6 Aug 2015 07:24:11 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:58643 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754734AbbHFLYI (ORCPT ); Thu, 6 Aug 2015 07:24:08 -0400 Date: Thu, 6 Aug 2015 12:23:53 +0100 From: Mark Brown To: Michal Suchanek Cc: "R, Vignesh" , devicetree , Brian Norris , Russell King , Tony Lindgren , Linux Kernel Mailing List , linux-spi , Huang Shijie , MTD Maling List , linux-omap@vger.kernel.org, David Woodhouse , "linux-arm-kernel@lists.infradead.org" Message-ID: <20150806112353.GT20873@sirena.org.uk> References: <20150731181745.GM20873@sirena.org.uk> <55BEF4AF.5090704@ti.com> <20150804155148.GR20873@sirena.org.uk> <55C0FD98.1090107@ti.com> <20150805115013.GJ20873@sirena.org.uk> <20150805124412.GN20873@sirena.org.uk> <20150806090202.GO20873@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="62KrrilqlZ2duPAE" Content-Disposition: inline In-Reply-To: X-Cookie: Please take note: User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1898 Lines: 48 --62KrrilqlZ2duPAE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Aug 06, 2015 at 12:01:37PM +0200, Michal Suchanek wrote: > However, I am familiar m25p80.c and as I understand it the controller > is basically supposed to implement m25p80.c in hardware when this flag > is set. But what in concrete terms is that supposed to mean? It's currently just an essentially undocumented flag on a message rather than something operating at the level of a flash chip. That's pretty much where Russell's comments come from. > If I was using m25p80.c to talk to anything but an actual flash chip > it would get me quite worried. Sure, but at the end of the day it's just emitting standard SPI messages which don't know anything about flash. If those messages are a sensible interface here then why bother with the flag, we can just pattern match on the format of the message. If that doesn't work then probably this isn't a great interface and a separate, application specific interface makes more sense. --62KrrilqlZ2duPAE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJVw0PJAAoJECTWi3JdVIfQlDwH/RoJjV1vtBZvIz6y2rNeg6SY /EngkfZbUpsCABFhzmUP0eF4uLs6R4JzzRaEbG02wW3XcEjn+l1eFywV4ab9iVuu QXlEYaxK6jChxAZWps+AGHXXZ8sBOKTc3rEjX1fv5ahCgjikPZ6/q2EsahqliE+L 87r0GR+Vslu5eedlvXytMPQiepzHxLAmoWiIeyA/fRJhpSyeh1VYB/LrUWsf/2tf B1HTFQeiYkbL2F/83qFZzEC+ODwYF08/7a/aaDQraEZ9dkTimjeLO6r9NxuF90iE F6ivbguXfkxBSil0BaJRL2PpVf3ZWAfFxOiMbIvr1HudheTnvm+7PLDrawgiux4= =RTgY -----END PGP SIGNATURE----- --62KrrilqlZ2duPAE-- -- 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/