From: "Steven A. Falco" <sfalco@harris.com>
To: Mike Frysinger <vapier.adi@gmail.com>
Cc: dwmw2@infradead.org, linux-mtd@lists.infradead.org
Subject: Re: [PATCH] Bug in m25p80.c during whole-chip erase
Date: Tue, 28 Apr 2009 09:40:34 -0400 [thread overview]
Message-ID: <49F70752.5030702@harris.com> (raw)
In-Reply-To: <8bd0f97a0904271426p30df3a97ke31af72dcf96531f@mail.gmail.com>
Mike Frysinger wrote:
> On Mon, Apr 27, 2009 at 17:10, Steven A. Falco wrote:
>> There is a logic error in "whole chip erase" for the m25p80 family. If
>> the whole device is successfully erased, erase_chip() will return 0, and
>> the code will fall through to the "else" clause, and do sector-by-sector
>> erase in addition to the whole-chip erase. This patch corrects that.
>>
>> Also, the MAX_READY_WAIT_COUNT is insufficient for an m25p16 connected
>> to a 400 MHz powerpc. Increasing it allows me to successfully program
>> the device on my board.
>
> in general, trying to set timeouts "close" to the spec gains nothing
> with spi flash devices. the timeout limit is hit only when an error
> occurs, and errors should not occur during the normal run of things.
> on the other side, having a timeout be wrongly hit when the device is
> operating correctly is a much worse situation to be in.
> -mike
>
Right. This chip takes 13 seconds (typical) to bulk erase, according to
the Numonyx data sheet. So increasing the timeout to account for such
a slow part is necessary, and allows me to successfully erase the part.
Are there any changes you'd like to see in this patch, or is it ok as
written?
Steve
next prev parent reply other threads:[~2009-04-28 13:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-27 21:10 [PATCH] Bug in m25p80.c during whole-chip erase Steven A. Falco
2009-04-27 21:26 ` Mike Frysinger
2009-04-28 13:40 ` Steven A. Falco [this message]
[not found] ` <49F70E43.9050103@colonel-panic.org>
2009-04-28 14:15 ` Steven A. Falco
2009-04-28 15:58 ` Mike Frysinger
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