usb-storage data errors

[DervishD <lkml@dervishd.net>]

    Hi all :)

    I'm having a problem with usb-storage devices under:

    - Two different kernels: 2.4.31 (vanilla) and 2.6.17 (Ubuntu).
    - Two different USB 2.0 cards (ALi chipset and VIA chipset).
    - So, two different drivers (OHCI and EHCI).
    - Two different usb-storage adapters (an external USB box from an
      unknown manufacturer and Conceptronic CIDE23U). Both are
      USB-to-IDE adapters.
    - Many different hard disks.
    - Both vfat and ext2/3 filesystems.
    - Perfect RAM (at least, that's what memtest says).
    - Correctly cooled system.

    The problem is the following: whenever I copy a lot of data to
the usb-storage device (more than a few GB's), the copy goes OK,
without an error, but when I compare the copied files with the
original files, sometimes a copied file is different. This does not
happen if I copy the files one by one, and it doesn't happens all the
time, sometimes the copy is perfect.

    In addition to this, from time to time the usb-storage adapters
(any of them, with any of the USB cards and any kernel) report a read
error, telling that some sector could not be read. This is false
because if I repeat the operation, the sector is correctly retrieved.
This can be related to some kind of timing problem, I don't know.

    The fact is that I cannot reproduce the problem reliably, so I
cannot give you a "recipe", except that it happens when I copy a lot
of data at a time.

    Any suggestion about how to narrow the problem down? Any more
data that you may need? A known bug? Am I doing any stupidity?

    Thanks a lot in advance :)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736 | http://www.dervishd.net
It's my PC and I'll cry if I want to... RAmen!