From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris brezillon Subject: Re: [RFC PATCH 1/9] mtd: nand: retrieve ECC requirements from Hynix READ ID byte 4 Date: Wed, 29 Jan 2014 11:29:59 +0100 Message-ID: <52E8D827.8010609@overkiz.com> References: <1389190924-26226-1-git-send-email-b.brezillon@overkiz.com> <1389190924-26226-2-git-send-email-b.brezillon@overkiz.com> <20140123014906.GY8919@ld-irv-0074> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140123014906.GY8919@ld-irv-0074> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Brian Norris Cc: Maxime Ripard , Rob Landley , Russell King , David Woodhouse , Grant Likely , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dev-3kdeTeqwOZ9EV1b7eY7vFQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Huang Shijie List-Id: devicetree@vger.kernel.org Hello Brian, On 23/01/2014 02:49, Brian Norris wrote: > + Huang > > Hi Boris, > > On Wed, Jan 08, 2014 at 03:21:56PM +0100, Boris BREZILLON wrote: >> The Hynix nand flashes store their ECC requirements in byte 4 of its id >> (returned on READ ID command). >> >> Signed-off-by: Boris BREZILLON > I haven't verified yet (perhaps Huang can confirm?), but this may be > similar to a patch Huang submitted recently. In his case, we found that > this table is actually quite unreliable and is likely hard to maintain. You mean these bytes are not reliable within the whole Hynix LP (Large Page) NAND product line ? > > Why do you need this ECC information, for my reference? Because the NAND flash available on the cubietruck board does not support the ONFI standard, and I thought this could be a option to retrieve the ECC strength requirements. Anyway, I added a new helper function to retrieve ecc informations from device tree (I'll post it in the 2nd version of this series). We'll see if this approach is accepted... > > Brian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html