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    SubjectRe: [PATCH 3/5] usb: gadget: gmidi: remove bus powered requirement on bmAttributes
    Date

    Hi,

    Krzysztof Opasiak <k.opasiak@samsung.com> writes:
    > [ text/plain ]
    >
    >
    > On 03/08/2016 08:43 AM, Felipe Balbi wrote:
    > (...)
    >
    >>>>> This is necessary because this driver is actually wrong in which is
    >>>>> asking for the host to power itself. This is not specified on USB-MIDI
    >>>>> specification, neither makes any sense since this configuration is
    >>>>> device specific.
    >>>>>
    >>>>> What is your suggestion to make it configurable? Maybe at compile-time?
    >>>>> I really don't know what is the best solution if this is not something
    >>>>> you like it.
    >>>>
    >>>> well, you could use our configfs-based gadget interface. You don't
    >>>> really need to use gmidi.ko at all. In fact, we wanna do away with any
    >>>> static modules and rely only on configfs. If configfs doesn't let you
    >>>> change what you want/need, then we can talk about adding support for
    >>>> those.
    >>>>
    >>>> bMaxPower and bmAttributes sound like good things to have configurable
    >>>> over configfs but beware of what the USB specification says about them,
    >>>> we cannot let users violate the spec by passing bogus values on these
    >>>> fields.
    >>>
    >>> I agree that we should move to configfs, but the truth is that these
    >>> legacy devices are still useful. They just do one thing, mostly, but
    >>
    >> yes, they are useful as they are. They don't need to be changed to be
    >> useful. Plus, you can have a gadget built with configfs that does only
    >> one thing. And you can do that with a simple shell script.
    >>
    >>> its easy and simple to setup and use. So I think before we have some
    >>
    >> so is configfs.
    >>
    >>> sort of preset library of configfs-based gadget drivers, we still need
    >>> these modules.
    >>
    >> there is already a library called libusbg.
    >
    > As libusbg itself is a little bit dead there is a fork called
    > libusbgx[1] and it is still active;)
    >
    > It already has support for f_midi so it is ready to use.

    heh, seems like usb libraries tend to get forked with an 'x' appended to
    their name. But thanks for the note.

    --
    balbi
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