RE: [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller

[Naga Sureshkumar Relli <nagasure@xilinx.com>]

Hi Miquel,

> -----Original Message-----
> From: Miquel Raynal [mailto:miquel.raynal@bootlin.com]
> Sent: Wednesday, December 12, 2018 2:40 PM
> To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> Cc: Boris Brezillon <boris.brezillon@bootlin.com>; 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 <michals@xilinx.com>;
> 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 <nagasure@xilinx.com> wrote on Wed, 12 Dec 2018
> 09:04:16 +0000:
> 
> > Hi Miquel,
> >
> > > -----Original Message-----
> > > From: Miquel Raynal [mailto:miquel.raynal@bootlin.com]
> > > Sent: Wednesday, December 12, 2018 1:42 PM
> > > To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> > > Cc: Boris Brezillon <boris.brezillon@bootlin.com>; 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 <michals@xilinx.com>;
> > > 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 <nagasure@xilinx.com> wrote on Wed, 12 Dec
> > > 2018
> > > 05:27:03 +0000:
> > >
> > > > 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
> Erased pages.
> > > > But bit[7:0] in ECC_Error_Count_Register(0x38) will update for each error occurred.
> > > > Link:
> > > > https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-ultr
> > > > ascale-
> > > registers.html and check for NAND module, ECC_Error_Count_Register.
> > > >
> > > > 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 error 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
> > > bitflips.
> > > >
> > > > If it is ok, I will update the driver and will send new patch, but
> > > > do you have any other
> > > comments on v12?
> > >
> > > Is 'nandbiterrs -i' running correctly now?
> > Yes, but with some changes in driver.
> > I have added the log and changes done in https://lkml.org/lkml/2018/11/23/705.
> 
> No, I don't see a working nandbiterrs there, sorry.
The log that I have attached is from mtd_nandbiterrs test
So as per ARASAN controller ECC mechanism, it will correct upto 24-bit. After that the test will fail.

I am running mtd-utils nandbiterr test now. Will let you know once I completed that.

Thanks,
Naga Sureshkumar Relli
> 
> 
> Thanks,
> Miquèl