Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932487AbbFTTNk (ORCPT ); Sat, 20 Jun 2015 15:13:40 -0400 Received: from mail-ig0-f177.google.com ([209.85.213.177]:33698 "EHLO mail-ig0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751528AbbFTTNc (ORCPT ); Sat, 20 Jun 2015 15:13:32 -0400 MIME-Version: 1.0 In-Reply-To: <1434639539-7517-1-git-send-email-anuragku@xilinx.com> References: <1434639539-7517-1-git-send-email-anuragku@xilinx.com> Date: Sat, 20 Jun 2015 21:13:31 +0200 Message-ID: Subject: Re: [RFC PATCH] mtd: spi-nor: Added flag check for quad io protocol for micron flash parts From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= To: Anurag Kumar Vulisha Cc: David Woodhouse , Brian Norris , =?UTF-8?B?TWFyZWsgVmHFoXV0?= , Huang Shijie , Ben Hutchings , Mika Westerberg , =?UTF-8?B?QmVhbiBIdW8g6ZyN5paM5paMIChiZWFuaHVvKQ==?= , "grmoore@altera.com" , "linux-mtd@lists.infradead.org" , Linux Kernel Mailing List , Mark Brown , punnaia@xilinx.com, harinik@xilinx.com, anirudh@xilinx.com, svemula@xilinx.com, Anurag Kumar Vulisha 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: 1595 Lines: 32 Hi, I don't really have enough knowledge to comment QUAD IO, I'll just include some general comments. On 18 June 2015 at 16:58, Anurag Kumar Vulisha wrote: > micron flash parts by default operates in extended spi protocol,which accepts > command on single line and can accept address & data on one,two and four lines > depending on the command sent.In set_quad_enable() we are enabling the quad io > protocol for micron flash parts by updating the EVCR register,in this method the > flash expects the command,address and data to be transmitted on all four data > lines which may not be supported on all qspi controllers.So READ_1_1_4 command > does not necessarily go out using those bus widths. > > So i have added SPI_QUAD_IO_PROTOCOL flag,which should be checked before enabling > the quad io protocol. Above description is a bit of pain to read & understand. Long sentences, lacking spaces after interpunction signs, small letters in "micron", "spi" etc., lines over 72 chars. You really could do better :) > @@ -55,6 +55,7 @@ struct flash_info { > #define SPI_NOR_DUAL_READ 0x20 /* Flash supports Dual Read */ > #define SPI_NOR_QUAD_READ 0x40 /* Flash supports Quad Read */ > #define USE_FSR 0x80 /* use flag status register */ > +#define SPI_QUAD_IO_PROTOCOL 0x100 /* use quad io protocol */ All defines use tab so follow this way (don't use space instead). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/