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    SubjectRe: [PATCHv3 3/4] usb: gadget: rename usb_gadget_driver::speed to max_speed
    Hi,

    On Fri, Aug 19, 2011 at 10:34:29PM -0400, Alan Stern wrote:
    > On Sat, 20 Aug 2011, Felipe Balbi wrote:
    >
    > > On Sat, Aug 20, 2011 at 12:33:01AM +0200, Michal Nazarewicz wrote:
    > > > From: Michal Nazarewicz <mina86@mina86.com>
    > > >
    > > > This commit renames the “speed” field of the usb_gadget_driver
    > > > structure to “max_speed”. This is so that to make it more
    > > > apparent that the field represents the maximum speed gadget
    > > > driver can support.
    > > >
    > > > This also make the field look more like fields with the same
    > > > name in usb_gadget and usb_composite_driver structures. All
    > > > of those represent the *maximal* speed given entity supports.
    > > >
    > > > After this commit, there are the following fields in various
    > > > structures:
    > > > * usb_gadget::speed - the current connection speed,
    > > > * usb_gadget::max_speed - maximal speed UDC supports,
    > >
    > > this will be handled inside the UDC itself, so why do you need to expose
    > > it ?
    >
    > I wondered about this too. It turns out that sometimes the gadget
    > driver really does need to know about the maximum speed supported by
    > the UDC hardware and driver.
    >
    > For example, suppose the gadget driver and the UDC both support high
    > speed, but the gadget is currently plugged into a USB-1.1 controller
    > and therefore running only at full speed. Then the gadget driver has
    > to respond to the Get-Device-Qualifier and Get-Other-Speed-Config
    > requests by sending the appropriate descriptors. But if the UDC
    > doesn't support high speed operation then the gadget driver has to
    > respond to those requests with a STALL.

    aa, good point :-)

    --
    balbi
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