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    SubjectRe: MAX_USBFS_BUFFER_SIZE
    On Wed, Mar 01, 2006 at 01:54:23PM -0800, Greg KH wrote:
    > On Wed, Mar 01, 2006 at 10:42:35PM +0100, Ren? Rebe wrote:
    > > So, queing alot URBs is the recommended way to sustain the bus? Allowing
    > > way bigger buffers will not be realistic?
    >
    > 16Kb is "way big" in the USB scheme of things aready. Look at the size
    > of your endpoint. It's probably _very_ small compared to that. So no,
    > larger buffer sizes is not realistic at all.

    As a data point, I have traces of a scanner session including a
    download of a 26Mb binary image using 524288 bytes logical blocks
    physically transferred with 61440 bytes bulk_in frames. Seems stable
    enough. IIRC the scanner-side controller chip has some advanced
    buffering just to handle that kind of bandwidth.

    ISTR a preliminary linux userland driver using libusb having problems
    keeping up with the scanner too. May very well have been an issue
    with the driver itself though, so I wouldn't read too much into that.

    OG.

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