From mboxrd@z Thu Jan 1 00:00:00 1970 From: Janusz Krzysztofik Subject: Re: [RFC PATCH v2 07/12] mtd: rawnand: ams-delta: Set port direction once per transfer Date: Wed, 08 Aug 2018 18:55:35 +0200 Message-ID: <3260564.acbQT1CZaz@z50> References: <20180718235710.18242-1-jmkrzyszt@gmail.com> <20180806222918.12644-8-jmkrzyszt@gmail.com> <20180807205752.32cd3e53@bbrezillon> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20180807205752.32cd3e53@bbrezillon> Sender: linux-kernel-owner@vger.kernel.org To: Boris Brezillon Cc: Linus Walleij , linux-omap@vger.kernel.org, Jonathan Corbet , Tony Lindgren , Richard Weinberger , linux-gpio@vger.kernel.org, Aaro Koskinen , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Marek Vasut , linux-mtd@lists.infradead.org, Miquel Raynal , Brian Norris , David Woodhouse , linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org Hi Boris, On Tuesday, August 7, 2018 8:57:52 PM CEST Boris Brezillon wrote: > On Tue, 7 Aug 2018 00:29:13 +0200 > Janusz Krzysztofik wrote: > > > In its current shape, the driver sets data port direction before each > > byte read/write operation, even during multi-byte transfers. Since > > performance of the driver is completely not acceptable on Amstrad Delta > > after it has been converted to GPIO bitbang, try to improve things a > > bit by setting the port direction only on first byte of each transfer. > ... > I'd suggest a slightly different approach where the data pins > direction state is stored in the the priv struct and only changed when > required. This way you just have to add a test in > ams_delta_read/write_byte(). Good idea, I'm going to use it, thanks. Once done, may I also move that one earlier in the series so that it can be applied while our discussion on GPIO bitmap changes still continues? Thanks, Janusz