From patchwork Wed Jun 8 21:01:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Dasu X-Patchwork-Id: 632502 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rQ1BQ6jDdz9t3V for ; Thu, 9 Jun 2016 07:03:42 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=Ctf3isz0; dkim-atps=neutral Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bAkc7-0004Hr-GU; Wed, 08 Jun 2016 21:02:11 +0000 Received: from mail-pa0-x241.google.com ([2607:f8b0:400e:c03::241]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bAkbs-00048f-2t for linux-mtd@lists.infradead.org; Wed, 08 Jun 2016 21:01:56 +0000 Received: by mail-pa0-x241.google.com with SMTP id ug1so1215565pab.1 for ; Wed, 08 Jun 2016 14:01:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=eh6Dg1ZDUA3M9HqAe998/Phrn3HNICWoLdPynS+u20M=; b=Ctf3isz0IQSi3LKyOzfYta55q/SPXxCW6JiYlR+nqYMUBy7KQXwV3oJabGA3YACj/6 v3TWErvT2e9o8N7feuvUAdFSMakC9NmVJ4fCjy+xbUL+IYencRGxeqz97tzkAY18ZoKE iGiZErNvAAYq1+oh6pLrk+gdX10yEf2xrO5xVGZG6mNWb14d8fDdjpTnthh+MCyiy2x6 zzv1VQ0/xbHg7jmscmLEC4boTMyHq7YhxrCgCoH5t2K/NgDQAe8gv7MKAKLcEQ1yaXb5 SedYm2FCHzn74lf81EJMLcb0v0L742tO3dMHq6FRctmOc7gXzSu1Xkpy8c8Feuxa2ynB vfOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=eh6Dg1ZDUA3M9HqAe998/Phrn3HNICWoLdPynS+u20M=; b=XVpDLgiUHtmi/evpQ4+cRIsCsmIy7v8r2o33QgYLoBbKtQmIx3nC8t/6CrkrRYwVCW J8zlDjLV4Mb/CO2uJRc6OBGdILYvdMCmPQxP7pH/RhtPvqn/oZTEPlKIlU2XBavbCcwM QVjqVOccDGAXWcAK67yuFPmzqgYoT4XEbGCc4jvgAsXayZB/UZkW6pWP8fB+vtQlTNtc ppYZNOoOkXXU6R9Ao+4gVb9B+iT5TNXAZQEd6/icluzAolSEx5mIygk1DCUUSeQzJ42S 5i9JrAUwY11ISm7ZlltpZBsC2IRnJPswZUOckTxl22Gv5A7v/J8M0JLhTsrsWuk24g0i WYxQ== X-Gm-Message-State: ALyK8tJiiNIPWgm5CNA9EGLZ0zCQd6LHEwVl1sC6LVd848ru+GJv+Y7rNQ156I8VviC80Q== X-Received: by 10.66.4.106 with SMTP id j10mr6307756paj.111.1465419695330; Wed, 08 Jun 2016 14:01:35 -0700 (PDT) Received: from mail.broadcom.com ([216.31.219.19]) by smtp.gmail.com with ESMTPSA id r82sm4498379pfd.42.2016.06.08.14.01.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 08 Jun 2016 14:01:34 -0700 (PDT) From: Kamal Dasu To: linux-mtd@lists.infradead.org, computersforpeace@gmail.com, boris.brezillon@free-electrons.com Subject: [V2, 2/2] mtd: brcmnand: Detect sticky ucorr ecc error on dma reads Date: Wed, 8 Jun 2016 17:01:21 -0400 Message-Id: <1465419681-6162-2-git-send-email-kdasu.kdev@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1465419681-6162-1-git-send-email-kdasu.kdev@gmail.com> References: <1465419681-6162-1-git-send-email-kdasu.kdev@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160608_140156_167225_16202134 X-CRM114-Status: GOOD ( 12.39 ) X-Spam-Score: -2.7 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [2607:f8b0:400e:c03:0:0:0:241 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (kdasu.kdev[at]gmail.com) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com, Kamal Dasu MIME-Version: 1.0 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org This change provides a fix for controller bug where nand controller could have a possible sticky error after a PIO followed by a DMA read. The fix retries a read if we see a uncorr_ecc after read to detect such sticky errors. The fix applies to only controller version 7.0 and 7.1. Signed-off-by: Kamal Dasu --- V2 Changes Restrict controller bug workaround to version 7.0 and 7.1 --- drivers/mtd/nand/brcmnand/brcmnand.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c index 212acb4..f1163c95 100644 --- a/drivers/mtd/nand/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/brcmnand/brcmnand.c @@ -1601,9 +1601,11 @@ static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip, struct brcmnand_controller *ctrl = host->ctrl; u64 err_addr = 0; int err; + static bool retry = true; dev_dbg(ctrl->dev, "read %llx -> %p\n", (unsigned long long)addr, buf); +try_dmaread: brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_COUNT, 0); if (has_flash_dma(ctrl) && !oob && flash_dma_buf_ok(buf)) { @@ -1625,6 +1627,22 @@ static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip, if (mtd_is_eccerr(err)) { /* + * On controller version and 7.0, 7.1 , DMA read after a + * prior PIO read that reported uncorrectable error, + * the DMA engine captures this error following DMA read + * cleared only on subsequent DMA read, so just retry once + * to clear a possible false error reported for current DMA + * read + */ + if ((ctrl->nand_version == 0x0700) || + (ctrl->nand_version == 0x0701)) { + if (retry) { + retry = false; + goto try_dmaread; + } + } + + /* * Controller version 7.2 has hw encoder to detect erased page * bitflips, apply sw verification for older controllers only */