From: Boris Brezillon <boris.brezillon@bootlin.com>
To: Naga Sureshkumar Relli <nagasure@xilinx.com>
Cc: "miquel.raynal@bootlin.com" <miquel.raynal@bootlin.com>,
"richard@nod.at" <richard@nod.at>,
"dwmw2@infradead.org" <dwmw2@infradead.org>,
"computersforpeace@gmail.com" <computersforpeace@gmail.com>,
"marek.vasut@gmail.com" <marek.vasut@gmail.com>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"nagasuresh12@gmail.com" <nagasuresh12@gmail.com>,
"robh@kernel.org" <robh@kernel.org>,
Michal Simek <michals@xilinx.com>
Subject: Re: [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller
Date: Sun, 18 Nov 2018 20:43:24 +0100 [thread overview]
Message-ID: <20181118204324.373ca9cc@bbrezillon> (raw)
In-Reply-To: <MWHPR02MB26234433484426F333E9B60EAFDC0@MWHPR02MB2623.namprd02.prod.outlook.com>
On Thu, 15 Nov 2018 09:34:16 +0000
Naga Sureshkumar Relli <nagasure@xilinx.com> wrote:
> Hi Boris & Miquel,
>
> I am updating the driver by addressing your comments, and I have one concern, especially in anfc_read_page_hwecc(),
> there I am checking for erased pages bit flips.
> Since Arasan NAND controller doesn't have multibit error detection beyond 24-bit( it can correct up to 24 bit),
> i.e. there is no indication from controller to detect uncorrectable error beyond 24bit.
Do you mean that you can't detect uncorrectable errors, or just that
it's not 100% sure to detect errors above max_strength?
> So I took some error count as default value(MULTI_BIT_ERR_CNT 16, I put this based on the error count that
> I got while reading erased page on Micron device).
> And during a page read, will just read the error count register and compare this value with the default error count(16) and if it is more
> Than default then I am checking for erased page bit flips.
Hm, that's wrong, especially if you set ecc_strength to something > 16.
> I am doubting that this will not work in all cases.
It definitely doesn't.
> In my case it is just working because the error count that it got on an erased page is 16.
> Could you please suggest a way to do detect erased_page bit flips when reading a page with HW-ECC?.
I'm a bit lost. Is the problem only about bitflips in erase pages, or
is it also impacting reads of written pages that lead to uncorrectable
errors.
Don't you have a bit (or several bits) reporting when the ECC engine
was not able to correct data? I you do, you should base the "detect
bitflips in erase pages" logic on this information.
next prev parent reply other threads:[~2018-11-18 19:43 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-09 5:00 [LINUX PATCH v12 0/3] Add support for Arasan NAND Flash controller Naga Sureshkumar Relli
2018-11-09 5:00 ` [LINUX PATCH v12 1/3] dt-bindings: mtd: arasan: Add device tree binding documentation Naga Sureshkumar Relli
2018-11-09 6:28 ` Boris Brezillon
2018-11-09 12:33 ` Naga Sureshkumar Relli
2018-11-09 12:54 ` Miquel Raynal
2018-11-09 13:19 ` Naga Sureshkumar Relli
2018-11-16 11:50 ` Martin Lund
2018-11-16 12:10 ` Martin Lund
2018-11-16 12:33 ` Michal Simek
2018-11-16 13:50 ` Naga Sureshkumar Relli
2018-11-16 14:22 ` Martin Lund
2018-11-09 5:00 ` [LINUX PATCH v12 2/3] mtd: rawnand: Add an option to get sdr timing mode number Naga Sureshkumar Relli
2018-11-09 5:00 ` [LINUX PATCH v12 3/3] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller Naga Sureshkumar Relli
2018-11-09 8:07 ` Boris Brezillon
2018-11-09 13:18 ` Naga Sureshkumar Relli
2018-11-09 23:03 ` kbuild test robot
2018-11-12 10:55 ` Martin Lund
2018-11-12 10:58 ` Boris Brezillon
2018-11-12 12:43 ` Naga Sureshkumar Relli
2018-11-15 9:34 ` Naga Sureshkumar Relli
2018-11-18 18:52 ` Miquel Raynal
2018-11-18 19:43 ` Boris Brezillon [this message]
2018-11-19 6:20 ` Naga Sureshkumar Relli
2018-11-19 8:02 ` Boris Brezillon
2018-11-20 7:02 ` Naga Sureshkumar Relli
2018-11-20 11:02 ` Boris Brezillon
2018-11-20 12:36 ` Miquel Raynal
2018-11-23 13:53 ` Naga Sureshkumar Relli
2018-12-12 5:27 ` Naga Sureshkumar Relli
2018-12-12 8:11 ` Miquel Raynal
2018-12-12 9:04 ` Naga Sureshkumar Relli
2018-12-12 9:09 ` Miquel Raynal
2018-12-12 13:07 ` Naga Sureshkumar Relli
2018-12-12 13:18 ` Miquel Raynal
2018-12-17 13:21 ` Naga Sureshkumar Relli
2018-12-17 16:41 ` Miquel Raynal
2018-12-18 5:33 ` Naga Sureshkumar Relli
2018-12-19 14:26 ` Miquel Raynal
2018-12-21 7:36 ` Naga Sureshkumar Relli
2019-01-28 6:04 ` Naga Sureshkumar Relli
2019-01-28 9:27 ` Miquel Raynal
2019-01-28 9:35 ` Naga Sureshkumar Relli
2019-06-19 4:44 ` Naga Sureshkumar Relli
2019-06-27 16:27 ` Miquel Raynal
2019-06-28 4:20 ` Naga Sureshkumar Relli
2018-11-15 16:45 ` Dan Carpenter
2018-11-20 16:24 ` Boris Brezillon
2018-12-04 9:18 ` Naga Sureshkumar Relli
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