From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.newsguy.com ([74.209.136.69]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1RXbsR-00045R-DX for linux-mtd@lists.infradead.org; Mon, 05 Dec 2011 16:58:52 +0000 Message-ID: <4EDCF840.7050107@newsguy.com> Date: Mon, 05 Dec 2011 08:58:40 -0800 From: Mike Dunn MIME-Version: 1.0 To: dedekind1@gmail.com Subject: Re: [PATCH v2] MTD: modify mtd api to return bitflip info on read operations References: <1322943640-11728-1-git-send-email-mikedunn@newsguy.com> <4EDB3295.6040201@bitbox.co.uk> <4EDB7B1D.60603@newsguy.com> <1323009827.9400.75.camel@sauron.fi.intel.com> <4EDB89E9.6070306@newsguy.com> <1323065234.2316.2.camel@koala> In-Reply-To: <1323065234.2316.2.camel@koala> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Peter Horton , linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 12/04/2011 10:07 PM, Artem Bityutskiy wrote: > On Sun, 2011-12-04 at 06:55 -0800, Mike Dunn wrote: >> So you're thinking that the driver would supply both ecc_strength and >> "scrublevel" (or maybe bb_threshold)? Would these go into struct mtd_info? > Probably yes. After all, UBI has no idea about what kind of flash is > that and what kind of ECC it uses and what bit-flip level needs > scrubbing. So I think this kind of information should come from the > driver or from the user via mtd sysfs files. What do you think? I'm not a flash expert, but that sounds reasonable, especially if the scrublevel parameter is optional, with UBI using ecc_strength as the default value. As for how to pass the parameter, sysfs might be a good idea for scrublevel, allowing it to be tunable without having to modify the driver if experience show that the driver author's original assumptions about how a block degrades were incorrect. Thanks, Mike