Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756403Ab2HPIZR (ORCPT ); Thu, 16 Aug 2012 04:25:17 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:33156 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752608Ab2HPIZO (ORCPT ); Thu, 16 Aug 2012 04:25:14 -0400 Date: Thu, 16 Aug 2012 11:25:07 +0300 From: Shmulik Ladkani To: dedekind1@gmail.com Cc: Richard Genoud , David Woodhouse , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/4] UBI: use the whole MTD device size to get bad_peb_limit Message-ID: <20120816112507.01b7c0f0@pixies.home.jungo.com> In-Reply-To: <1345043331.3393.151.camel@sauron.fi.intel.com> References: <1341937423-16516-1-git-send-email-richard.genoud@gmail.com> <1341937423-16516-4-git-send-email-richard.genoud@gmail.com> <1345043331.3393.151.camel@sauron.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1632 Lines: 44 Hi Artem, Richard, On Wed, 15 Aug 2012 18:08:51 +0300 Artem Bityutskiy wrote: > 1. Invalid blocks are block that contain one or more bad bits beyond > ECC. I would remove this one sentence from the log, it is misleading; invalid blocks are not necessarily related to ECC. > if (CONFIG_MTD_UBI_BEB_LIMIT > 0) { > - int percent = CONFIG_MTD_UBI_BEB_LIMIT; > - int limit = mult_frac(ubi->peb_count, percent, 100); > + int per1024 = CONFIG_MTD_UBI_BEB_LIMIT; > + int limit, device_pebs; > + uint64_t device_size; > + > + /* > + * Here we are using size of the entire flash chip and > + * not just the MTD partition size because the maximum > + * number of bad eraseblocks is a percentage of the > + * whole device and bad eraseblocks are not fairly > + * distributed over the flash chip. So the worst case > + * is that all the bad eraseblocks of the chip are in > + * the MTD partition we are attaching (ubi->mtd). > + */ > + device_size = mtd_get_device_size(ubi->mtd); > + device_pebs = mtd_div_by_eb(device_size, ubi->mtd); > + limit = mult_frac(device_pebs, per1024, 1024); > > /* Round it up */ > - if (mult_frac(limit, 100, percent) < ubi->peb_count) > + if (mult_frac(limit, 1024, per1024) < ubi->peb_count) Oops... should be: + if (mult_frac(limit, 1024, per1024) < device_pebs) Regards, Shmulik -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/