Unlocking flash problem with the epxa10db device
Louie Boczek
louie at calimatech.com
Fri Sep 20 09:52:44 EDT 2002
Sounds good to me. I could have gone either way. So I actually fixed
it the way you want.
On a side note, is there any reason that the entire flash is unlocked on
boot instead of just the filesystem. I am referencing the unlock code
in epxa10db-flash.c.
thanks
louie
Christopher Hoover wrote:
>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.
>
>-ch
>
>
>-----Original Message-----
>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
>Louie Boczek
>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
>following problem.
>
>I was not able to write to the flash and found the problem lied in the
>unlocking code.
>In the epxa10db-flash.c:epxa10db_mtd_init() routine it calls:
>
> mymtd->unlock(mymtd, mymtd->eraseregions[i].offset + j *
>mymtd->eraseregions[i].erasesize, 4);
>
>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))
> return -EINVAL;
>
>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.
>
>thanks
>louie
>
>
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