[lkml]   [2012]   [Jan]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: loading firmware while usermodehelper disabled.
    On Mon, Jan 2, 2012 at 1:09 PM, Jack Stone <> wrote:
    > What about USB "class" drivers e.g. usb-storage. They handle any device
    > that reports itself as a usb mass storage device. There could be a
    > device that needs to be bootstrapped before it becomes a generic usb
    > mass storage device. Do we really want to have to write a new driver
    > that is almost identical to the generic driver but handles the USB
    > firmware correctly.

    I'd hope that the generic driver just expose enough interfaces that
    you could basically do a "firmware-load" driver that just loads the
    firmware and then attaches the device to the generic driver.

    So instead of duplicating the driver, or teaching the generic driver
    about magic setup stuff, you could do a "specialized" driver for that
    particular device (more likely, that manufacturers devices) and then
    have some way to hand it over.

    Of course, in the end it does matter what the "class" is. For storage
    devices, we really do want the kernel to handle things for us
    entirely. For other kinds of devices (and the isight camera does come
    to mind) I suspect it's entirely fine to just say "whatever, we don't
    care enough, just have some udev rules, load things from user space,
    and no, you cannot have a videochat active over a suspend/resume

    So while I think kernel drivers should generally strive for "you can
    suspend/resume without user space even noticing", I do think that it
    depends on the particular device just *how* strict you should be about
    that rule. Some devices just don't need that kind of attention.

    IOW, I think the kernel should *strive* for doing the right thing, and
    I think the firmware loader right now makes it unnecessarily hard to
    do things right, but at the same time there are no black-and-white
    absolute rules. There are always going to be exceptions where somebody
    says "this is a crap device, and it's simply not worth worrying


     \ /
      Last update: 2012-01-02 22:25    [W:0.020 / U:9.852 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site