From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga11.intel.com ([192.55.52.93]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U2FzB-0001O6-Mv for linux-mtd@lists.infradead.org; Mon, 04 Feb 2013 06:57:02 +0000 Message-ID: <1359961124.13791.1.camel@sauron.fi.intel.com> Subject: Re: question about mtd_torturetest.c From: Artem Bityutskiy To: "Gupta, Pekon" Date: Mon, 04 Feb 2013 08:58:44 +0200 In-Reply-To: <20980858CB6D3A4BAE95CA194937D5E73E995A7B@DBDE01.ent.ti.com> References: <50F9023D.5040408@freescale.com> <50F93F65.90805@parrot.com> <50FCB75D.1000200@freescale.com> <50FD02EA.5050209@parrot.com> <50FD0554.8030108@freescale.com> <50FD073C.8050209@parrot.com> <50FD0981.8050507@freescale.com> <50FD0B3D.2070803@parrot.com> <50FD0BE9.3020506@freescale.com> <50FF9068.1030709@freescale.com> <1359737889.2942.17.camel@sauron.fi.intel.com> <20980858CB6D3A4BAE95CA194937D5E73E995A7B@DBDE01.ent.ti.com> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-DWbSArhPK/BidL9McPG8" Mime-Version: 1.0 Cc: Huang Shijie , Lin Wei-B34918 , "linux-mtd@lists.infradead.org" , David Woodhouse , Matthieu CASTET Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-DWbSArhPK/BidL9McPG8 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2013-02-04 at 05:19 +0000, Gupta, Pekon wrote: > > On Wed, 2013-01-23 at 15:25 +0800, Huang Shijie wrote: > > > Hi all: > > > > > > The mtd_torturetest.c uses the 55/AA patterns to torture the nand > > block. > > > Are the 55/AA patterns more tougher then the random data? > >=20 > > Probably not, please, improve the test. > >=20 >=20 > (0x55/0xAA/0x55) pattern ensures that _all_ bits in the byte transition f= rom 0-> 1, and 1->0, > Whereas, a random pattern may miss a bit-cell or miss transition sequence= , of an bad bit-cell. > Exercising each bit both ways is important so as to differentiate a bad b= it-cell (permanent error) from read-disturb errors (temporary error). >=20 > For read-disturb: http://download.micron.com/pdf/presentations/events/fla= sh_mem_summit_jcooke_inconvenient_truths_nand.pdf Sure, I did not mean remove those, I meant that random data test can also be added and that would be an improvement. --=20 Best Regards, Artem Bityutskiy --=-DWbSArhPK/BidL9McPG8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iQIcBAABAgAGBQJRD1wkAAoJECmIfjd9wqK0iVIQALJtyGCNjJJHE5Uq9z6wR2AK J9DOlGDvTDdQZHmOFmlnuW4+GAFFI4cuFEGAcswibjN1uTThMq8clX0aVkYu82DZ 26xdpl8Y4IzxGiOFotCAiqB/YwgDfWg7ZMunf7rV/8AiftJ/nyZohGmAm+69sI6v 9Ivy8mEiTv/p85n74w1VVd8SHf3d8ChSnZzwKYzYlORRgLXaQXB7Gg/uP9O2LU1W ptbMnwtkPirmpsu/IhmPtEZqQQqz3qTjW9nHZQQrfxtWkNiD7CiHy4RTlwT7/AF2 KoU1Z4sVGeKt656+Vkw40QUEbNXTK1/M76SxxZOE+YZK8ksKsssEhqLebPXeCEbx bc68CN7kRkYoQXcMp6Gsb5hF6/2zvO6TAOYP4iKWzEkO1ieLcWhigAD37PsgM6y0 ZGsde2YVLj5A2ebQopWEbBA/uvTrgYjYB4Vnl+Tp0vnTm9ZummvxN68vnYqRm/Pg 9bie7qEnndiRNkNUfuC9f5isXBLoqfZujEvfzPvzM687PdmhfcfZG96XwY0vckTa BU/NTs7y/bTH9f5gYw/XTXaNAicbLCZ5OKK5s52GqCjK9CUp2/g9ci6e6iryQ6V/ TP/C8DHggxbSjq3AeRAGDLsYqM34b3wXV7P1wZRNKXMEEOJg8vZdgYJp89U/0wf2 TwPStsjvUeXnbrTH3kk1 =jg9+ -----END PGP SIGNATURE----- --=-DWbSArhPK/BidL9McPG8--