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From: David Wuertele <dave-gnus@bfnet.com>
Date: Tue, 22 Apr 2003 15:56:23 -0700
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Subject: mtd and devfs
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Is there any reason why mtd wouldn't work under devfs?
I'm running 2.4.18 plus some vendor patches.  I've got a nand flash
that is recognized on boot:

  STWX225 NAND Flash initializing...
  PFLASH_CNTL before MOD: 80after MOD: 80
  NAND device: Manufacture ID: 0xec, Chip ID: 0x73 (Samsung KM29U128T) Chip size: 2000000
  Creating 5 MTD partitions on "Samsung KM29U128T":
  0x00000000-0x00200000 : "MTD partition 0"
  mtd: Giving out device 0 to MTD partition 0
  0x00200000-0x00400000 : "MTD partition 1"
  mtd: Giving out device 1 to MTD partition 1
  0x00400000-0x00c00000 : "MTD partition 2 - root FS"
  mtd: Giving out device 2 to MTD partition 2 - root FS
  0x01f00000-0x01ffc000 : "MTD partition 3"
  mtd: Giving out device 3 to MTD partition 3
  0x01ffc000-0x02000000 : "MTD partition 4"
  mtd: Giving out device 4 to MTD partition 4
  STW4X225 NAND Flash initialized.

This results in devices under devfs:

  # ls -R /dev/mtd

  /dev/mtd:
  0
  0ro
  1
  1ro
  2
  2ro
  3
  3ro
  4
  4ro

But when I try to read from these, my system hangs before it ever gets
to the nand_read() function:

  # head /dev/mtd/0 > fred

Whether I try to read or write to the /dev/mtd/0 device, the system
hangs hard.  The nand_read() function has a printk as its first
statement, but the console never prints this, so I think there is
something wrong with the read dispatch.  Could there be issues with my
use of devfs?

Thanks,
Dave