From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pa0-x231.google.com ([2607:f8b0:400e:c03::231]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VAl1t-0000bv-Df for linux-mtd@lists.infradead.org; Sat, 17 Aug 2013 18:15:14 +0000 Received: by mail-pa0-f49.google.com with SMTP id ld10so3124129pab.22 for ; Sat, 17 Aug 2013 11:14:51 -0700 (PDT) Date: Sat, 17 Aug 2013 11:14:47 -0700 From: Brian Norris To: Huang Shijie Subject: Re: [PATCH v4 6/6] mtd: update the ABI document about the ecc step size Message-ID: <20130817181447.GC5034@norris.computersforpeace.net> References: <1376619009-8622-1-git-send-email-b32955@freescale.com> <1376619009-8622-7-git-send-email-b32955@freescale.com> <1376660759.2089.358.camel@sauron.fi.intel.com> <20130817032644.GA27332@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130817032644.GA27332@gmail.com> Cc: Huang Shijie , linux-mtd@lists.infradead.org, dwmw2@infradead.org, pekon@ti.com, Artem Bityutskiy List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Aug 16, 2013 at 11:26:47PM -0400, Huang Shijie wrote: > On Fri, Aug 16, 2013 at 04:45:59PM +0300, Artem Bityutskiy wrote: > > On Fri, 2013-08-16 at 10:10 +0800, Huang Shijie wrote: > > > + > > > +What: /sys/class/mtd/mtdX/ecc_step_size > > > +Date: May 2013 > > > +KernelVersion: 3.10 > > > +Contact: linux-mtd@lists.infradead.org > > > +Description: > > > + The size of each ECC step which is used for ECC. > > > + Note that some devices will have multiple ecc steps within each > > > + writesize region. > > > > Actually this phrase is a bit confusing because it may be interpreted as > > that one write-size may have ECC steps of multiple sizes. Would you > > re-phrase, may be? > What's about the following: > ----------------------------------------------------------------- > The size of each ECC step which is used for ECC. > Note that some devices will have multiple ecc steps within each > writesize region, and the ecc steps share the same size. > ----------------------------------------------------------------- I took pieces of your message and rewrote it myself. Diff pasted below (I edited ecc_strength to be less redundant and added a few details that were worth mentioning). Let me know if you want to revise it, but I'll push it to l2-mtd.git. Brian --- Documentation/ABI/testing/sysfs-class-mtd | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd index 3105644..a795582 100644 --- a/Documentation/ABI/testing/sysfs-class-mtd +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -128,9 +128,8 @@ KernelVersion: 3.4 Contact: linux-mtd@lists.infradead.org Description: Maximum number of bit errors that the device is capable of - correcting within each region covering an ecc step. This will - always be a non-negative integer. Note that some devices will - have multiple ecc steps within each writesize region. + correcting within each region covering an ECC step (see + ecc_step_size). This will always be a non-negative integer. In the case of devices lacking any ECC capability, it is 0. @@ -173,3 +172,16 @@ Description: This is generally applicable only to NAND flash devices with ECC capability. It is ignored on devices lacking ECC capability; i.e., devices for which ecc_strength is zero. + +What: /sys/class/mtd/mtdX/ecc_step_size +Date: May 2013 +KernelVersion: 3.10 +Contact: linux-mtd@lists.infradead.org +Description: + The size of a single region covered by ECC, known as the ECC + step. Devices may have several equally sized ECC steps within + each writesize region. The step size counts only the data area, + not the spare area. + + It will always be a non-negative integer. In the case of + devices lacking any ECC capability, it is 0.