From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.230] helo=mgw-mx03.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1MnqwQ-0005F7-VH for linux-mtd@lists.infradead.org; Wed, 16 Sep 2009 09:36:51 +0000 Subject: Re: Doubt regarding mtd test ( mtd_oobtest ) interpretation of oob data ! From: Artem Bityutskiy To: Murali N In-Reply-To: <630851df0909160009w35efd6b2kb058593b59e1be66@mail.gmail.com> References: <630851df0909160009w35efd6b2kb058593b59e1be66@mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 16 Sep 2009 12:36:10 +0300 Message-Id: <1253093770.3778.7.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2009-09-16 at 12:39 +0530, Murali N wrote: > Hi All, > i have a doubt on how the OOB data is being managed in MTD driver. > Recently i have enabled mtd-tests to test my driver for mtd > compliance.After i ran "mtd_oobtest" i was messed up with test and > come up with few questions: > > 1) Is these tests are well validated? can i trust these tests 100% > compliant to MTD API specification? > 2) In "mtd_oobtest" ( drivers/mtd/tests/ ), there was a "test 4 of 5" > in this there was a few checks for writing/reading end off OOB data. > - In these tests what is the significance of using > "ooboffs" in OOB_AUTO mode? > 3) Is MTD driver ask the below NAND driver to read/write the oob data > integral of oobavail size in OOB_AUTO mode? How MTD driver behaves if > it is not!!! > 4) Finally, can anyone please explain bit more about OOB_PLACE mode? > also the significance of ooboffs field usage? I do not understand your questions, and I do not quite remember these modes already, but the below code probably explains things well: /* * oob operation modes * * MTD_OOB_PLACE: oob data are placed at the given offset * MTD_OOB_AUTO: oob data are automatically placed at the free areas * which are defined by the ecclayout * MTD_OOB_RAW: mode to read raw data+oob in one chunk. The oob data * is inserted into the data. Thats a raw image of the * flash contents. */ typedef enum { MTD_OOB_PLACE, MTD_OOB_AUTO, MTD_OOB_RAW, } mtd_oob_mode_t; -- Best Regards, Artem Bityutskiy (Артём Битюцкий)