From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gX4PX-0005L8-Od for linux-mtd@lists.infradead.org; Wed, 12 Dec 2018 13:18:49 +0000 Date: Wed, 12 Dec 2018 14:18:25 +0100 From: Miquel Raynal To: Naga Sureshkumar Relli Cc: Boris Brezillon , "robh@kernel.org" , "richard@nod.at" , "linux-kernel@vger.kernel.org" , "marek.vasut@gmail.com" , "linux-mtd@lists.infradead.org" , "nagasuresh12@gmail.com" , Michal Simek , "computersforpeace@gmail.com" , "dwmw2@infradead.org" Subject: Re: [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller Message-ID: <20181212141825.69711c57@xps13> In-Reply-To: References: <1541739641-17789-1-git-send-email-naga.sureshkumar.relli@xilinx.com> <1541739641-17789-4-git-send-email-naga.sureshkumar.relli@xilinx.com> <20181118204324.373ca9cc@bbrezillon> <20181119090246.49060019@bbrezillon> <20181120120244.7d2442b5@bbrezillon> <20181120133624.3fa4742d@xps13> <20181212091135.1d0cc9a6@xps13> <20181212100931.149b0cac@xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Naga, Naga Sureshkumar Relli wrote on Wed, 12 Dec 2018 13:07:42 +0000: > Hi Miquel, >=20 > > -----Original Message----- > > From: Miquel Raynal [mailto:miquel.raynal@bootlin.com] > > Sent: Wednesday, December 12, 2018 2:40 PM > > To: Naga Sureshkumar Relli > > Cc: Boris Brezillon ; robh@kernel.org; ric= hard@nod.at; linux- > > kernel@vger.kernel.org; marek.vasut@gmail.com; linux-mtd@lists.infradea= d.org; > > nagasuresh12@gmail.com; Michal Simek ; > > computersforpeace@gmail.com; dwmw2@infradead.org > > Subject: Re: [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support fo= r Arasan > > NAND Flash Controller > >=20 > > Hi Naga, > >=20 > > Naga Sureshkumar Relli wrote on Wed, 12 Dec 2018 > > 09:04:16 +0000: > > =20 > > > Hi Miquel, > > > =20 > > > > -----Original Message----- > > > > From: Miquel Raynal [mailto:miquel.raynal@bootlin.com] > > > > Sent: Wednesday, December 12, 2018 1:42 PM > > > > To: Naga Sureshkumar Relli > > > > Cc: Boris Brezillon ; robh@kernel.org; > > > > richard@nod.at; linux- kernel@vger.kernel.org; > > > > marek.vasut@gmail.com; linux-mtd@lists.infradead.org; > > > > nagasuresh12@gmail.com; Michal Simek ; > > > > computersforpeace@gmail.com; dwmw2@infradead.org > > > > Subject: Re: [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support > > > > for Arasan NAND Flash Controller > > > > > > > > Hi Naga, > > > > > > > > Naga Sureshkumar Relli wrote on Wed, 12 Dec > > > > 2018 > > > > 05:27:03 +0000: > > > > =20 > > > > > Hi Boris & Miquel, > > > > > > > > > > An update to my comments on thread https://lkml.org/lkml/2018/11/= 15/656. > > > > > In this I said, will take a default error count value as 16 and > > > > > during page read, will check the error count Register value with > > > > > this and if it is equal to or greater than the default count(16) = then I am checking for =20 > > Erased pages. =20 > > > > > But bit[7:0] in ECC_Error_Count_Register(0x38) will update for ea= ch error occurred. > > > > > Link: > > > > > https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-ultr > > > > > ascale- =20 > > > > registers.html and check for NAND module, ECC_Error_Count_Register.= =20 > > > > > > > > > > I mean previously I dependent on Total error count value > > > > > (bit[16:8]), but we can simply check for bit[7:0] To see the erro= r occurred or not. > > > > > I tried with this approach and I don't see any issues with that. > > > > > I ran ubifs with this and I am able to see the bit[7:0] count is > > > > > updated for erased page read and then will Use > > > > > nand_chech_erased_ecc_chunk() to see the =20 > > > > bitflips. =20 > > > > > > > > > > If it is ok, I will update the driver and will send new patch, but > > > > > do you have any other =20 > > > > comments on v12? > > > > > > > > Is 'nandbiterrs -i' running correctly now? =20 > > > Yes, but with some changes in driver. > > > I have added the log and changes done in https://lkml.org/lkml/2018/1= 1/23/705. =20 > >=20 > > No, I don't see a working nandbiterrs there, sorry. =20 > The log that I have attached is from mtd_nandbiterrs test > So as per ARASAN controller ECC mechanism, it will correct upto 24-bit. A= fter that the test will fail. There is a distinction between: 1/ The driver fails to correct more than 24-bit and advertise the caller that the page read is somehow corrupted. 2/ The driver fails to correct more than 24-bit but does not complain about it. In our case, the caller (the test tool) will compare the page written and read: if it do not match it means the driver is broken because the driver reported a successful operation despite the fact that it returned a corrupted page. You are in the second case, we expect the driver to behave like in 1/. >=20 > I am running mtd-utils nandbiterr test now. Will let you know once I comp= leted that. Yes please, prefer using the userspace tools. Thanks, Miqu=C3=A8l