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    SubjectRe: [PATCH 2/3] firmware: Add CONFIG_BUILTIN_FIRMWARE option
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    > so using "/" within the name parameter for request_firmware() is
    > actually forbidden. I know that some driver authers think it is a good
    > idea, but it is not.

    Can you explain why it is allowed now? And maybe why the API was
    designed in a way that easily allows it?

    > I explained this a couple of times. The request_firmware() is an
    > abstract mechanism that can request a firmware file. The location of
    > the firmware file is up to the userspace. The kernel requests a
    > particular file and that is it. All namespacing has to be done by the
    > firmware helper script (nowadays udev). That the current
    > implementation of the firmware helper maps the filename 1:1 to a file
    > under /lib/firmware/ just works, but doesn't have to work all the
    > time. It is not the agreed contract between kernel and userspace.

    I don't buy this argument. I could agree if you said that the "agreed
    contract" between the kernel and userspace is for the kernel to request
    a firmware file /keyed by an arbitrary, null-terminated string/.

    The fact that it is usually stored on a filesystem where / means a
    directory (and thus grouping) can be seen as a nice convenience of the
    filesystem storage, but if firmware was stored elsewhere then you could
    degrade to the simple key-based lookup that happens to allow "/" as a
    character in the keys.

    And because the kernel is nice, it allows userspace to use a filesystem
    storage by not using paths like "../../lib/firmware/asdf". But
    fundamentally, I don't even see anything wrong with that.

    Put another way, you can have pretty arbitrary firmware firmware names
    (though since humans need to handle them you want printable characters),
    and I don't see why now all the sudden you would treat "/" specially by
    *explicitly* disallowing it.

    b43 comes with 22 firmware files for a single driver, and groups them
    using "b43/<name>". What you're proposing will make firmware fail
    *again* for all users, and we got a *LOT* of flak from all kinds of
    stakeholders (not just the users) when firmware upgrades were required,
    doing it again for such a petty reason is ridiculous.

    johannes
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