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    SubjectRe: [PATCHv2] MTD: Add UBI reboot notifier
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    On Fri, 2010-02-12 at 14:45 +0100, Norbert van Bolhuis wrote:
    > Artem Bityutskiy wrote:
    > > FYI, I do not like this patch, because it is not solving the problem, it
    > > just makes the problem less likely. I.e., you are still screwed if you
    > > reboot while some other task is doing erasure. Indeed, the background
    > > thread is not the only task which may do erases.
    > >
    > > I'm not going to revert this patch, but wanted to let you know that I
    > > think it was my mistake to push it.
    > >
    >
    > so, how to solve this properly ?
    >
    > probably the only way is the reboot notifier of the MTD chip driver
    > (for NOR flash only cmdset_0001 has one).

    Well. UBI itself does not have problems with half-erased eraseblocks. As
    the comment to the patch says, this is for a strange platform where the
    boot loader panics when it encounters a half-erased EB.

    So the most proper fix is to fix the boot-loader. Remember, a power cut
    can introduce half-erased EBs, and you cannot address this in SW.

    For clean reboots, you would need to have a reboot notifier in the MTD
    lever, not in UBI. This notifier should:

    1. Finish the current erase operation.
    2. Prevent further erase operations.

    The UBI patch is not a good solution.

    --
    Best Regards,
    Artem Bityutskiy (Артём Битюцкий)

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