From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2644C282D7 for ; Wed, 30 Jan 2019 09:27:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F151218DA for ; Wed, 30 Jan 2019 09:27:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548840421; bh=tUq72VSzYnNFVYGVT8BF1ZCDNBx1RY5oWvsyX6oy5MQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=SYsG8kq/5mTPuK76Mm1EXFPQ4sTGDtkQvoRFLKQvwRxyy9m+zUh0yXDd5ySCxdFU4 3ZcBeLNiAS8ykiSGEAFvvcxeZdo6sl4+L7Pf5Xi8etTG53pD8Jl5KjDcDZ5L+FHCSs BfJ2GmnkZai4q1vDmWQuc/5M1dzxhDevw1WIZmDY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730453AbfA3J07 (ORCPT ); Wed, 30 Jan 2019 04:26:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:36664 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726427AbfA3J07 (ORCPT ); Wed, 30 Jan 2019 04:26:59 -0500 Received: from bbrezillon (91-160-177-164.subs.proxad.net [91.160.177.164]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1A76820882; Wed, 30 Jan 2019 09:26:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548840418; bh=tUq72VSzYnNFVYGVT8BF1ZCDNBx1RY5oWvsyX6oy5MQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ONG0lOxvnARllj/oVOC/uCAsh30UDos1+xUH2PSbsFCAuPQPT6UW8SyDPxK9P3Tgn RXRHnWnTObp0rwsdvjPWzv1SLvA6vTRyBnCPelNWWfGTW8VVtM3bBicDXIcnqCBV0K CAxEBjvtFNzvSXliH5gczu7xspCf1cMdNPADzpT4= Date: Wed, 30 Jan 2019 10:26:46 +0100 From: Boris Brezillon To: Marek Vasut Cc: masonccyang@mxic.com.tw, broonie@kernel.org, Geert Uytterhoeven , Simon Horman , juliensu@mxic.com.tw, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-spi@vger.kernel.org, sergei.shtylyov@cogentembedded.com, zhengxunli@mxic.com.tw Subject: Re: [PATCH v7 1/2] spi: Add Renesas R-Car Gen3 RPC-IF SPI controller driver Message-ID: <20190130102646.23c798fc@bbrezillon> In-Reply-To: References: <1548227352-14910-1-git-send-email-masonccyang@mxic.com.tw> <1548227352-14910-2-git-send-email-masonccyang@mxic.com.tw> <67fa5f94-886b-f09c-c93d-832e427ffec8@gmail.com> <0b3ea94f-a4f3-0780-301b-f88ff2ad2fb1@gmail.com> <2d762c16-d714-9171-9450-b6adf1a6509c@gmail.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Jan 2019 08:15:25 +0100 Marek Vasut wrote: > >> > So far as I know that HF is provided by Cypress only and > >> > any mass production product use the component which is provided by only > >> > one provider > >> > will be a big risk. > >> > > >> > Compare to HF, there are more provider of SPI/Octa could support the > >> > mass production product > >> > as their second provider. > >> > > >> > In addition, from the technical points of view, mx25uw51245g is more > >> > powerful than HF and > >> > good for complicate user application, i.e., OTA and so on. > >> > >> Did you consider protocol overhead too ? I don't think you can compare > >> them just by raw numbers of pins and bus frequency. > >> > >> Note that over-the-air update (if that's what you mean by OTA) is > >> completely separate from the underlying storage device. > > > > It's key feature of mx25uw51245g supports Read-while-Write capability > > that allows read access from one memory bank while writing to another > > memory bank. > > Note that this sales pitch is rather off-topic. > Fully agree with Marek on that point. The discussion is about supporting both HF and SPI-MEM modes (or, at least have a plan to support HF at some point) not figuring out which option is better.