From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga02.intel.com ([134.134.136.20]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UFjJt-0003MP-DV for linux-mtd@lists.infradead.org; Wed, 13 Mar 2013 10:54:05 +0000 Message-ID: <1363172096.11441.11.camel@sauron.fi.intel.com> Subject: Re: [PATCH V4 1/3] mtd: add new fields to nand_flash_dev{} From: Artem Bityutskiy To: Huang Shijie Date: Wed, 13 Mar 2013 12:54:56 +0200 In-Reply-To: <1362653364-29993-2-git-send-email-b32955@freescale.com> References: <1362653364-29993-1-git-send-email-b32955@freescale.com> <1362653364-29993-2-git-send-email-b32955@freescale.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org, computersforpeace@gmail.com, dwmw2@infradead.org, linux-kernel@vger.kernel.org Reply-To: artem.bityutskiy@linux.intel.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2013-03-07 at 18:49 +0800, Huang Shijie wrote: > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > index 591eeeb..f0a9d93 100644 > --- a/include/linux/mtd/nand.h > +++ b/include/linux/mtd/nand.h > @@ -578,6 +578,8 @@ struct nand_chip { > * @erasesize: eraseblock size in bytes (determined from the extended ID if 0) > * @chipsize: total chip size in MiB > * @options: stores various chip bit options > + * @id_len: The valid length of the @id. > + * @oobsize: OOB size > */ > struct nand_flash_dev { > char *name; > @@ -592,6 +594,8 @@ struct nand_flash_dev { > unsigned long chipsize; > unsigned long erasesize; > unsigned long options; > + unsigned long id_len; > + unsigned long oobsize; > }; Why are these of type 'long', which is 64 bits in 64-bit architectures, which seems to be unnecessarily big. Wouldn't 'unsigned int' be enough? Also, can we avoid having the 'id_len' field? Can the end of the sequence of ID's be marked with a '0' or '0xFF' marker instead? -- Best Regards, Artem Bityutskiy