From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yk0-f181.google.com ([209.85.160.181]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WhIMu-0002Tn-8w for linux-mtd@lists.infradead.org; Mon, 05 May 2014 12:51:41 +0000 Received: by mail-yk0-f181.google.com with SMTP id q200so6110944ykb.12 for ; Mon, 05 May 2014 05:51:18 -0700 (PDT) Date: Mon, 5 May 2014 09:50:47 -0300 From: Ezequiel Garcia To: "Gupta, Pekon" Subject: Problems in Out of tree TI SDK omap2-nand driver (Re: [PATCH 3/3] nandtest: Introduce multiple reads & check iterations) Message-ID: <20140505125047.GA11106@arch.cereza> References: <1398690859-11494-1-git-send-email-ezequiel@vanguardiasur.com.ar> <1398690859-11494-4-git-send-email-ezequiel@vanguardiasur.com.ar> <20980858CB6D3A4BAE95CA194937D5E73EACA5DB@DBDE04.ent.ti.com> <20140505103335.GF2873@arch.cereza> <20980858CB6D3A4BAE95CA194937D5E73EACA6B9@DBDE04.ent.ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20980858CB6D3A4BAE95CA194937D5E73EACA6B9@DBDE04.ent.ti.com> Cc: Brian Norris , "linux-mtd@lists.infradead.org" , Guido =?iso-8859-1?Q?Mart=EDnez?= , Artem Bityutskiy List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , I've changed the subject of this mail, since it seems we've moved from the discussion. On 05 May 10:58 AM, Gupta, Pekon wrote: > > However, I know of some issues in OMAP NAND driver bundled with > 3.2 kernel, which might be helpful in nailing down your specific issue. > FWIW, I'm not using such driver anymore. Right after spotting this, we've ran the *same* test on the mainline driver, which passed. This was the kick we needed to start using mainline (we also need mainline for other reasons). > (1) 3.2 kernel does not have concept of bitflip_threshold, so by default > scrubbing and peb_torture happens even for single bit-flips. So please > pull-in following patch series. > [PATCH v2 0/7] mtd: Change meaning of -EUCLEAN return code on reads > http://lists.infradead.org/pipermail/linux-mtd/2012-April/040945.html > Isn't this series related to the higher-level treatment of bitflips? In that case, it's not related to the issue I got. Keep in mind that this simple test failed in our v3.2 stress (using this nandtest patch): * erase * write * read * read * ... * read (20 times) > (2) OMAP NAND in 3.2 kernel does not factor bit-flips in empty pages > Hence if empty pages with bit-flips are encountered, then it treats them > like programmed pages and expects a ECC correction on them. But as > empty pages do not have ECC stored in OOB, the driver bails out giving > 'uncorrectable ecc' read errors. > Since the test doesn't involve empty pages, I'd say this is not relevant. If you're still interested in debugging the problematic TI SDK omap2-nand driver, I suggest that you try using this nandtest patch and see how it goes. Despite you saying drivers can fail the test, I think it's still a nice test. Keep in mind the nandtest tool reports the number of corrected ECC errors after reads, so if that number is adding-up and increasing you can even use this patch to see this evolution. All in all, I think it's still a nice improvement on stock nandtest. -- Ezequiel Garcia, VanguardiaSur www.vanguardiasur.com.ar