Unlocking flash problem with the epxa10db device
ch at murgatroid.com
Fri Sep 20 00:52:14 EDT 2002
I wrote cfi_intelext_varsize_frob(). It is behaving as intended.
You have to unlock/lock/erase/etc. an *entire* block/sector at a time.
There's no way to unlock 4 bytes and leave the other (erasesize - 4)
bytes locked. So the function returns EINVAL if the size isn't an even
"multiple" of the block size(s). ("Multiple" here is not meant strictly
in the mathematical sense; consider variably-sized blocks.)
You'll find the other functions behave identically, e.g. erase.
From: linux-arm-kernel-admin at lists.arm.linux.org.uk
[mailto:linux-arm-kernel-admin at lists.arm.linux.org.uk] On Behalf Of
Sent: Thursday, September 19, 2002 8:11 PM
To: ARM Linux kernel Mailinglist
Subject: Unlocking flash problem with the epxa10db device
I just started working with the Altera Excalibur board and ran into the
I was not able to write to the flash and found the problem lied in the
In the epxa10db-flash.c:epxa10db_mtd_init() routine it calls:
mymtd->unlock(mymtd, mymtd->eraseregions[i].offset + j *
which eventually calls "cfi_cmdsetc_001.c:cfi_intelext_varsize_frob()"
in this routine there is a check to make sure that the region being
unlocked is the whole region with the check:
if ((ofs + len) & (regions[i].erasesize -1))
this fails since the call was only to unlock 4 bytes not erasesize. So
I fixed the problem by changing the call to mymtd->unlock() to pass the
erasesize instead of 4.
But the question is, should "cfi_intelext_varsize_frob()" check to see
if the whole region is specifed or should it unlock the region that the
specified location is located. I think the later.
I am using the linux-2.4.18-rmk7 but I also checked linux-2.4.19 and the
problem is also there.
I am new to this, I hope I gave enough and thorough informartion.
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