From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from wproxy.gmail.com ([64.233.184.206]) by canuck.infradead.org with esmtp (Exim 4.43 #1 (Red Hat Linux)) id 1CorPC-0004gt-Lb for linux-mtd@lists.infradead.org; Wed, 12 Jan 2005 17:55:59 -0500 Received: by wproxy.gmail.com with SMTP id 36so639538wra for ; Wed, 12 Jan 2005 14:55:57 -0800 (PST) Message-ID: <6934efce05011214553465438@mail.gmail.com> Date: Wed, 12 Jan 2005 14:55:57 -0800 From: Jared Hulbert To: Josh Boyer In-Reply-To: <1105569824.3896.44.camel@weaponx.rchland.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit References: <20050111215102.GA6289@wohnheim.fh-wedel.de> <6934efce050112084111ef438c@mail.gmail.com> <6934efce0501121430471e55a8@mail.gmail.com> <1105569824.3896.44.camel@weaponx.rchland.ibm.com> Cc: MTD List , David Woodhouse Subject: Re: JFFS3 & performance Reply-To: Jared Hulbert List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > That's not true. Eraseblocks can go bad during operation. That doesn't > mean that the whole device returns bad data. Sure, during an erase... How does a checksum help you here? > CRCs are needed. Or rather, some form of checksum is needed. Bits flip > during operation on NOR as well. I've seen it happen. It's rare, but > as David put it in an IRC conversation "it's a sanity check on the > hardware". > > There's sort of multiple threads on this topic, so maybe check some of > those. We even got Joern to agree they're needed :). I respectfully disagree. I don't think checksums are needed to protect you from NOR read errors *unless* the checksums are the only thing protecting the filesystem from bad things like crashes, power failures, and bugs.