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    SubjectRe: [PATCH 0/8] MUSE: Userspace backed MTD v3
    Miquel,

    ----- Ursprüngliche Mail -----
    >> Does in-band and OOB data need to be handled together?
    >
    > Short answer: yes.
    >
    >> If so, then two requests is not a good option.
    >
    > More detailed answer:
    >
    > There is a type of MTD device (NAND devices) which are composed, for
    > each page, of X in-band bytes plus Y out-of-band metadata bytes.
    >
    > Accessing either the in-band data, or the out-of-band data, or both at
    > the same time are all valid use cases.
    >
    > * Read operation details:
    > From a hardware point of view, the out-of-band data is (almost)
    > always retrieved when the in-band data is read because it contains
    > meta-data used to correct eventual bitflips. In this case, if both
    > areas are requested, it is highly non-efficient to do two requests,
    > that's why the MTD core allows to do both at the same time.
    > * Write operation details:
    > Even worse, in the write case, you *must* write both at the same
    > time. It is physically impossible to do one after the other (still
    > with actual hardware, of course).
    >
    > That is why it is preferable that MUSE will be able to access both in
    > a single request.

    By single request we meant FUSE op-codes. The NAND simulator in Userspace
    will see just one call. My plan is to abstract it in libfuse.

    Thanks,
    //richard

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