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[216.31.211.11]) by mx.google.com with ESMTPSA id j15sm1618023qaa.6.2013.11.14.11.00.06 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 14 Nov 2013 11:00:08 -0800 (PST) Date: Thu, 14 Nov 2013 11:00:04 -0800 From: Brian Norris To: Ezequiel Garcia Subject: Re: [PATCH v4 06/31] mtd: nand: pxa3xx: Add documentation about the controller Message-ID: <20131114190004.GP9468@ld-irv-0074.broadcom.com> References: <1383837455-30721-1-git-send-email-ezequiel.garcia@free-electrons.com> <1383837455-30721-7-git-send-email-ezequiel.garcia@free-electrons.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1383837455-30721-7-git-send-email-ezequiel.garcia@free-electrons.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131114_140030_962240_32A50CB9 X-CRM114-Status: GOOD ( 13.39 ) X-Spam-Score: -2.0 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (computersforpeace[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -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 -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Cc: Lior Amsalem , devicetree@vger.kernel.org, Jason Cooper , Tawfik Bayouk , linux-doc@vger.kernel.org, Willy Tarreau , Huang Shijie , linux-mtd@lists.infradead.org, Gregory Clement , Daniel Mack , Thomas Petazzoni , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org On Thu, Nov 07, 2013 at 12:17:10PM -0300, Ezequiel Garcia wrote: > Given there's no public specification to this date, and in order > to capture some important details and singularities about the > controller let's document them once and for good. Made a few small tweaks for spelling and such (see the following diff) and pushed patches 5 through 14 to l2-mtd.git/next. Thanks, Brian diff --git a/Documentation/mtd/nand/pxa3xx-nand.txt b/Documentation/mtd/nand/pxa3xx-nand.txt index 00e601c..840fd41 100644 --- a/Documentation/mtd/nand/pxa3xx-nand.txt +++ b/Documentation/mtd/nand/pxa3xx-nand.txt @@ -36,7 +36,7 @@ OOB, one per chunk read. So, in order to achieve reading (for instance), we issue several READ0 commands (with some additional controller-specific magic) and read two chunks of 2080B (2048 data + 32 spare) each. -The driver accomodates this data to expose the NAND core a contiguous buffer +The driver accommodates this data to expose the NAND core a contiguous buffer (4096 data + spare) or (4096 + spare + ECC + spare + ECC). ECC @@ -81,7 +81,7 @@ an *entire* page. Factory bad blocks handling =========================== -Given the ECC BCH requires to layout the device's pages in a splitted +Given the ECC BCH requires to layout the device's pages in a split data/OOB/data/OOB way, the controller has a view of the flash page that's different from the specified (aka the manufacturer's) view. In other words, @@ -109,5 +109,5 @@ disabled by using the NAND_BBT_NO_OOB_BBM option in the driver. The rationale for this is that there's no point in marking a block as bad, because good blocks are also 'marked as bad' (in the OOB BBM sense) under normal usage. -Instead, the drive relies in the bad block table alone, and should only perform +Instead, the driver relies on the bad block table alone, and should only perform the bad block scan on the very first time (when the device hasn't been used).