From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from db3ehsobe003.messaging.microsoft.com ([213.199.154.141] helo=db3outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UCQRB-0007MG-Ev for linux-mtd@lists.infradead.org; Mon, 04 Mar 2013 08:08:00 +0000 Message-ID: <5134566C.2090405@freescale.com> Date: Mon, 4 Mar 2013 16:08:12 +0800 From: Huang Shijie MIME-Version: 1.0 To: Subject: Re: [PATCH V3 1/3] mtd: add new fields to nand_flash_dev{} References: <1359349039-11510-1-git-send-email-b32955@freescale.com> <1359349039-11510-2-git-send-email-b32955@freescale.com> <1360684037.12703.117.camel@sauron.fi.intel.com> <1362234094.2745.9.camel@sauron> <513437DF.2030505@freescale.com> <1362383434.2943.5.camel@sauron> In-Reply-To: <1362383434.2943.5.camel@sauron> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: quoted-printable Cc: dwmw2@infradead.org, computersforpeace@gmail.com, Huang Shijie , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , =E4=BA=8E 2013=E5=B9=B403=E6=9C=8804=E6=97=A5 15:50, Artem Bityutskiy =E5= =86=99=E9=81=93: > On Mon, 2013-03-04 at 13:57 +0800, Huang Shijie wrote: >> The current code uses the @id to store the device id(byte 1). >> But if we use the 8 bytes id data as the keyword, and expand the @id >> field to 8byte array, >> the device id is the second byte now. All the added zeros are for the > I do not think you need to store the full array of ID's. Device ID's fo= r > all the 4 of above chips are different, which is enough to distinguish > between them. > > The only thing you need to add is the OOB size field to 'struct > nand_flash_dev'. > If i only add the oob size field. There will be two items with the same=20 Device ID in nand_flash_ids table, one has oob_size, one does not have. such as: {"NAND 8GIB 3,3V 8-bit", 0xDE, 0, 8192, 0, LP_OPTIONS}, {"NAND 8GIB 3,3V 8-bit", 0xDE, 0, 8192, 0, LP_OPTIONS, 640}, //OOB=20 size is 640. How can i distinguish them? In which case, i choose the item with the=20 oob_size, and in which case, i choose the item without the oobsize? thanks Huang Shijie