MT25Q Advanced Sector Protection support

[Stefan Roese]

Hi,

I'm right now working on a board equipped with an MT25QU128ABA1ESE.
And after doing some intensive QSPI NOR tests, one sector (at 0x40000)
seems to be permanently locked. The normal unlocking does not seem to
help:

# flash_eraseall -u /dev/mtd0
flash_eraseall has been replaced by `flash_erase <mtddev> 0 0`; please 
use it
Erasing 64 Kibyte @ 40000 -- 22 % complete libmtd: error!: MEMERASE64 
ioctl failed for eraseblock 4 (mtd0)
         error 5 (Input/output error)
flash_erase: error!: /dev/mtd0: MTD Erase failure
              error 5 (Input/output error)
Erasing 64 Kibyte @ 110000 -- 100 % complete

My best guess right now is that somehow the nonvolatile locking via the
advanced sector protection is active and locking this sector.

Does anyone have some ideas on how to continue here? Is there some
ongoing work to support the Micron advanced sector protection in Linux?
Or did I miss something trivial perhaps?

Thanks,
Stefan