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    SubjectRe: USB device allocation
    Hi Peter.

    >> And one should cure the disease (too short dev_t) instead of the
    >> symptoms (inventing devfs).

    > Ah, but devfs *does* cure the disease. (It has the distinction
    > of being the only such cure so far, not counting vaporware.)
    > If used in no-compatibility mode, it can dynamically assign
    > 32-bit device numbers, without any major/minor split. Are you
    > suggesting that someone out there has need for more than 1<<32
    > device nodes?

    > And before you complain that this breaks compatibility with
    > someone (LILO and rdev need to be taught not to hardcode root
    > dev numbers in), remember that a bigger kdev_t carries the same
    > disadvantage.

    There appears to be several people claiming that a bigger kdev_t
    breaks compatibility with lots of programs, and I find this rather
    hard to understand, so can somebody explain this to me please?

    In particular, please explain what's wrong with implementing a 32-bit
    or 64-bit kdev_t defined such that nodes where all except the bottom
    16 bits are zero, it is defined as a "compatibility node"?

    As an example, and assuming a 32-bit kdev_t split into 16-bit major
    and 16-bit minor fields, the 16-bit major 0 would be defined this way,
    and would be treated as being the equivalent of the current node
    numbers recast as a 16-bit minor with the major 0.

    Best wishes from Riley.

    +----------------------------------------------------------------------+
    | There is something frustrating about the quality and speed of Linux |
    | development, ie., the quality is too high and the speed is too high, |
    | in other words, I can implement this XXXX feature, but I bet someone |
    | else has already done so and is just about to release their patch. |
    +----------------------------------------------------------------------+
    * ftp://ftp.MemAlpha.cx/pub/rhw/Linux
    * http://www.MemAlpha.cx/Linux/


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