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    SubjectRe: [PATCH 13/15] MTD: add few workarounds to nand system for SmartMedia/xD chips.
    On Mon, 22 Feb 2010, Maxim Levitsky wrote:

    > On Mon, 2010-02-22 at 22:25 +0100, Thomas Gleixner wrote:
    > > On Mon, 22 Feb 2010, Maxim Levitsky wrote:
    > >
    > > > * Add an option NAND_SMARTMEDIA that can be set by nand driver
    > > > If set, it will cause separate ID table to be used, which includes
    > > > mask rom devices and new xD cards
    > >
    > > Why that option ? We can just extend the existing ids table and be
    > > done. No extra magic needed.
    > >
    >
    > Two reasons.
    >
    > First of all several xD chips (I belive the Type M) have exactly same
    > IDs like normal nand chips. However they don't report capabilities about
    > pagesize, blocksize, etc.

    You mean that crap ?

    + /* xD only */
    + {"xD 512MiB 3,3V", 0xDC, 512, 512, 0x4000, XD_TYPEM},
    + {"xD 1GiB 3,3V", 0xD3, 512, 1024, 0x4000, XD_TYPEM},
    + {"xD 2GiB 3,3V", 0xD5, 512, 2048, 0x4000, XD_TYPEM},

    Oh well, that's a perfect example of designed by comittee shit.

    They abuse the 2k chips IDs and define crappy sizes just to fit the
    stupid spec.

    > I am confident that these cards have an internal FTL and controller, and
    > just 'emulate' that nand interface.

    Either that or the adapter translates the 512B commands to 2K
    commands. I bet on the latter. AFAIK are xD cards just as stupid as
    SmartMedia ones, i.e. bare NAND chips in a flat plastic housing with
    gold contacts.

    > Also, my card reports write protect, although, xD cards don't have any
    > 'switch' to make them protected.

    Neither have SmartMedia Cards nor bare NAND chips. WP is a pin on the
    interface which is controlled by the adapter hardware.

    > Even if there were readonly ROM xD cards (the odds of this are virtually
    > zero), these won't just expose this in WP bit.

    Hmm, I wonder whether that horror has the WP bit inverted.

    Thanks,

    tglx


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