Restart problems after writing to mtdblock?

Paul Nash paulnash at
Sat Nov 30 09:46:22 EST 2002

Power fail is not a concern -- this only occurs in the case of a software
reboot of the chip without power loss.  An external reset is not an issue.
Flash chips don't store state as to their last read mode across power
failure anyway.

-----Original Message-----
From: Jörn Engel [mailto:joern at] 
Sent: Wednesday, November 27, 2002 11:39 PM
To: Paul Nash
Cc: linux-mtd at
Subject: Re: Restart problems after writing to mtdblock?

On Wed, 27 November 2002 18:33:31 -0800, Paul Nash wrote:
> Partially answering my question, it looks like I was partly correct.  
> It appears that MTD is setup to lazily delay a reset to read array 
> mode until an actual read request comes along.  In my case, this is 
> fatal.

Frankly, if the hardware doesn't reset the flash chips on reboot, you have
broken hardware and have to deal with it. A reboot_notifier would work,
unless you have a power fail. Not good.

Hacking cfi_cmdset_0001.c to bring the chips back into read mode whenever
possible would work better, breaking only on power fail during a write or
erase operation. Still not good.

So, unless you want to live with the problem, there is no alternative to
fixing the hardware.


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