linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Vignesh Raghavendra <vigneshr@ti.com>
To: <Tudor.Ambarus@microchip.com>, <john.garry@huawei.com>,
	<linux-mtd@lists.infradead.org>
Cc: broonie@kernel.org, fengsheng5@huawei.com
Subject: Re: flash_lock issue for n25q 128mb spi nor part
Date: Tue, 17 Dec 2019 14:27:33 +0530	[thread overview]
Message-ID: <6667f429-4732-d098-843a-7a030010f192@ti.com> (raw)
In-Reply-To: <c1a92c89-020d-0847-b7bf-41dbfd9b972e@microchip.com>

Hi Tudor,

On 12/16/2019 11:39 PM, Tudor.Ambarus@microchip.com wrote:
[...]

>>
>> But, as you may see, it seems that my change to spi_nor_write() is still
>> required to stop the first unlock failure message, but it needs to be
>> relocated to after write_err label, as we now jump there for
>> spi_nor_wait_till_ready() failure. I guess the equivalent relocation is
>> also required for spi_nor_erase().
>>
>> Or maybe spi_nor_wait_till_ready() should clear this flag always.
> 
> I reproduced this on a n25q256a, with both erase and write. Did a lock,
> an erase or write, and then the unlock raises an error on the read back test:
> it receives 0x02 to write (the prev operation let the SR.WE set to 1),
> and after write, it reads back 0x00 (which is correct, WE is de-asserted).
> 
> What is pretty strange is that Micron says about erase or program operations
> that: "When the operation is in progress, the write in progress bit is set
> to 1. The write enable latch bit is cleared to 0, whether the operation is
> successful or not".
> 
> So what I guess it happens, is that when an erase/write command tries to
> modify a software protected area, the flash completely ignores the command,
> so no Write In Progress, and no clearing of the WE.
> 


From PROGRAM Operations section of mt25q datasheet:

" When a command is applied to a protected sector, the command is not
executed, the write enable latch bit remains set to 1, and flag status
register bits 1 and 4 are set."

So, Data sheet is quite clear about this and SW would need to clear WEL
(if required) after write failure.

Regards
Vignesh

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  reply	other threads:[~2019-12-17  8:58 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-02 17:28 flash_lock issue for n25q 128mb spi nor part John Garry
2019-12-03  9:45 ` Tudor.Ambarus
2019-12-03 10:31   ` John Garry
2019-12-03 11:07     ` Tudor.Ambarus
2019-12-03 11:44       ` John Garry
2019-12-03 12:05         ` Tudor.Ambarus
2019-12-03 12:27           ` Tudor.Ambarus
2019-12-03 12:35             ` John Garry
2019-12-03 13:57               ` John Garry
2019-12-03 14:44                 ` Tudor.Ambarus
2019-12-03 15:29                   ` John Garry
2019-12-04 11:10                     ` John Garry
2019-12-16 18:09                       ` Tudor.Ambarus
2019-12-17  8:57                         ` Vignesh Raghavendra [this message]
2019-12-17 10:09                           ` John Garry
2020-01-09 10:36                           ` John Garry
2020-01-10 11:51                             ` Tudor.Ambarus
2020-01-10 11:56                               ` John Garry
2020-01-15  9:28                                 ` John Garry
2020-03-09 10:15                               ` [RESEND PATCH 1/2] mtd: spi-nor: Clear WEL bit when erase or program errors occur Tudor.Ambarus
2020-03-09 10:15                                 ` [RESEND PATCH 2/2] mtd: spi-nor: Fix description of the sr_ready() return value Tudor.Ambarus
2020-03-09 15:04                                 ` [RESEND PATCH 1/2] mtd: spi-nor: Clear WEL bit when erase or program errors occur John Garry
2020-03-23 17:58                                   ` Tudor.Ambarus
2019-12-03 14:16               ` [PATCH] mtd: spi-nor: Fix the write Status Register on micron flashes Tudor.Ambarus
2019-12-03 14:50                 ` [PATCH v2] mtd: spi-nor: Fix the writing of the " Tudor.Ambarus
2019-12-04 10:18                   ` John Garry
2020-01-09 19:14                   ` Miquel Raynal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=6667f429-4732-d098-843a-7a030010f192@ti.com \
    --to=vigneshr@ti.com \
    --cc=Tudor.Ambarus@microchip.com \
    --cc=broonie@kernel.org \
    --cc=fengsheng5@huawei.com \
    --cc=john.garry@huawei.com \
    --cc=linux-mtd@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).