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From: Marek Vasut <marex@denx.de>
To: Michal Suchanek <hramrach@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	zajec5@gmail.com, Alison Chaiken <alison_chaiken@mentor.com>,
	Ben Hutchings <ben@decadent.org.uk>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	"Bean Huo \(beanhuo\)" <beanhuo@micron.com>,
	"grmoore@altera.com" <grmoore@altera.com>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] MTD: spi-nor: add flag to not use sector erase.
Date: Fri, 1 May 2015 01:13:50 +0200	[thread overview]
Message-ID: <201505010113.50293.marex@denx.de> (raw)
In-Reply-To: <35add8df33b17e2354d9496eba8597d9d8488f30.1430430153.git.hramrach@gmail.com>

On Thursday, April 30, 2015 at 11:13:12 PM, Michal Suchanek wrote:
> The sector size of the flash memory is unclear from datasheet or may
> possibly vary between chips so add a flag to always use 4k blocks.
> 
> Currently 4k blocks are always used when possible but in the future
> somebody might want to do some optimizations with sector erase.
> 
> Signed-off-by: Michal Suchanek <hramrach@gmail.com>

I _think_ you might be able to determine the size, no ?

One way is to ask the vendor, but you can also try something like:
1) erase the whole SPI NOR
2) overwrite it with zeroes (or ones ? I think it should be all ones after 
erasing).
3) Erase sector 0
4) Read some 128 KiB back
5) Observe what is the difference.

Best regards,
Marek Vasut

       reply	other threads:[~2015-04-30 23:13 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1430430153.git.hramrach@gmail.com>
     [not found] ` <35add8df33b17e2354d9496eba8597d9d8488f30.1430430153.git.hramrach@gmail.com>
2015-04-30 23:13   ` Marek Vasut [this message]
2015-05-01  7:05     ` [PATCH 3/3] MTD: spi-nor: add flag to not use sector erase Michal Suchanek
2015-05-01 10:50       ` Jonas Gorski
2015-05-01 14:20       ` Marek Vasut
2015-05-04 11:11         ` Michal Suchanek
2015-05-04 12:12           ` Marek Vasut
2015-05-04 13:18             ` Michal Suchanek
2015-05-04 13:35               ` Marek Vasut
2015-05-04 13:39                 ` Michal Suchanek
2015-05-04 14:11                   ` Marek Vasut
2015-05-01 21:56   ` Rafał Miłecki
     [not found] ` <02f7510acb9b6dbb3a5a6cd5bb287762eb4d22c1.1430430153.git.hramrach@gmail.com>
2015-04-30 23:09   ` [PATCH 1/3] MTD: m25p80: fix write return value Marek Vasut
2015-05-20 23:45   ` Brian Norris
2015-05-21  8:33     ` Michal Suchanek

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