[U-Boot] fw_setenv on protected flash

[Eibach, Dirk]

Hi Stefan,

> > Some of your recent cfi flash driver enhancements have made flash 
> > protect/unprotect work on our NOR based platforms (S29GL512). Good 
> > news so far, but as a consequence fw_setenv is woking no more:
> > MTD erase error on /dev/mtd5: Input/output error
> > Error: can't write fw_env to flash
> > 
> > Also flash_unlock from mtd_utils is not doing the trick:
> > Could not unlock MTD device: /dev/mtd5
> > 
> > Unprotecting flash in u-boot before booting linux makes 
> this work, but 
> > this is probably no good idea.
> > 
> > So what is the recommended workflow for fw_setenv on 
> protected flash?
> 
> Linux support for this enhanced sector protection (PPB) has 
> just been accepted into mainline Linux. You need include this 
> patch if you are working with an older kernel version:
> 
> http://patchwork.ozlabs.org/patch/213602/
> 
> And you also need to enable this feature in your dts file as 
> described in the patch description.

Ah, thanks a lot.

So the recommended workflow (with patch and dts changes applied) would
be:
flash_unlock
fw_setenv
flash_lock
?

Cheers
Dirk