From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ob0-f170.google.com ([209.85.214.170]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vog0p-0005Uo-E0 for linux-mtd@lists.infradead.org; Thu, 05 Dec 2013 20:59:08 +0000 Received: by mail-ob0-f170.google.com with SMTP id wp18so18606779obc.29 for ; Thu, 05 Dec 2013 12:58:42 -0800 (PST) Received: from ld-irv-0074.broadcom.com (5520-maca-inet1-outside.broadcom.com. [216.31.211.11]) by mx.google.com with ESMTPSA id tr10sm79589047obb.6.2013.12.05.12.58.40 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 05 Dec 2013 12:58:41 -0800 (PST) Date: Thu, 5 Dec 2013 12:58:38 -0800 From: Brian Norris To: linux-mtd@lists.infradead.org Subject: Re: [PATCH 3/4] mtd: nand: support Micron READ RETRY Message-ID: <20131205205838.GL27149@ld-irv-0074.broadcom.com> References: <1386274800-22013-1-git-send-email-computersforpeace@gmail.com> <1386274800-22013-3-git-send-email-computersforpeace@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386274800-22013-3-git-send-email-computersforpeace@gmail.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Caught a simple bug when testing with a non-READ_RETRY NAND. See below. On Thu, Dec 05, 2013 at 12:19:59PM -0800, Brian Norris wrote: ... > One thing I'm not sure about: do all relevant (i.e., ONFI-capable) NAND drivers > support SET_FEATURES properly? If not, then it's possible that this could break > nand_do_read_ops for such drivers. Not sure what the best method of handling > that would be. ... > --- a/drivers/mtd/nand/nand_base.c > +++ b/drivers/mtd/nand/nand_base.c ... > @@ -1512,8 +1535,27 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from, > nand_wait_ready(mtd); > } > > - if (mtd->ecc_stats.failed - ecc_failures) > - ecc_fail = true; > + if (mtd->ecc_stats.failed - ecc_failures) { > + retry_mode++; This increment shouldn't be done for all ECC failures, but only for failures where there are remaining read-retry modes (i.e., flash that support read retry). > + if (retry_mode < chip->read_retries) { > + pr_debug("ECC error; performing READ RETRY %d\n", > + retry_mode); > + > + ret = nand_set_read_retry(mtd, > + retry_mode); > + if (ret < 0) > + break; > + > + /* Reset failures */ > + mtd->ecc_stats.failed = ecc_failures; > + continue; > + } else { > + /* No more retry modes; real failure */ > + ecc_fail = true; > + } > + } > + > + buf += bytes; > } else { > memcpy(buf, chip->buffers->databuf + col, bytes); > buf += bytes; I'll send a v2 with the following extra diff: diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 82efd819f31b..aeafcdce6cc0 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -1536,8 +1536,8 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from, } if (mtd->ecc_stats.failed - ecc_failures) { - retry_mode++; - if (retry_mode < chip->read_retries) { + if (retry_mode + 1 < chip->read_retries) { + retry_mode++; pr_debug("ECC error; performing READ RETRY %d\n", retry_mode); --- Brian