Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751400AbaDZDKb (ORCPT ); Fri, 25 Apr 2014 23:10:31 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:52977 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751034AbaDZDKa (ORCPT ); Fri, 25 Apr 2014 23:10:30 -0400 Date: Sat, 26 Apr 2014 11:10:13 +0800 From: Huang Shijie To: Marek Vasut Cc: Huang Shijie , Graham Moore , ggrahammoore@gmail.com, Geert Uytterhoeven , Artem Bityutskiy , Sascha Hauer , Jingoo Han , linux-kernel@vger.kernel.org, Yves Vandervennet , linux-mtd@lists.infradead.org, Insop Song , Alan Tull , Sourav Poddar , Brian Norris , David Woodhouse , Dinh Nguyen Subject: Re: [PATCH V3] Add support for flag status register on Micron chips. Message-ID: <20140426031011.GA4811@localhost.localdomain> References: <1398175396-7560-1-git-send-email-grmoore@altera.com> <201404250442.33197.marex@denx.de> <20140425015245.GB24530@localhost> <201404260012.24311.marex@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201404260012.24311.marex@denx.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 26, 2014 at 12:12:24AM +0200, Marek Vasut wrote: > > > > the drivers may fills this hook itself, so the code should like this: > > > > -------------------------------------------------- > > > > > > > > if ((info->flags & USE_FSR) && > > > > > > > > nor->wait_till_ready == spi_nor_wait_till_fsr_ready) > > > > > > > > nor->wait_till_ready = spi_nor_wait_till_fsr_ready; > > > > > > > > -------------------------------------------------- > > > > > > I sense a misdesign of the SPI NOR subsystem here. The subsystem and the > > > driver compete for a function pointer here ? I guess one should have > > > precedence in some way then ... and also, they should be two different > > > pointers, where the subsystem decides which to use. > > > > the subsystem do not decides which one to use, the driver decides which one > > to use. > > > > If driver has its own @wait_till_ready , it means the driver knows the > > feature, and has implemented it in its own @wait_till_ready. > > > > If the driver does not fill any wait_till_ready, it means the driver will > > use the default @wait_till_ready. We can treat the > > spi_nor_wait_till_fsr_ready as a default hook too. > > I see the driver overwriting a hook previously set by the subsystem. This not sure ;) The driver set the hooks before the subsystem set these hooks. If the driver has already set the @wait_till_ready hook before it calls the spi_nor_scan, the subsystem will not set the hook anymore. Please see the spi_nor_check(). thanks Huang Shijie -- 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/