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    Subject[PATCH] incrase usbdevfs bulk buffer size
    Increase the usbdevfs buffer size limit.

    I hit this limit with running ehci in the VM. The a single ehci
    qTD transfer buffer can be 5 pages long, that is 20K. The current devio bulk
    transfer limit is 16K. I am not sure why the bulk transfer limit
    is 16K. I can complicate the user space part to work around that,
    but it seems much simpler just allow usbdevfs to accept bigger buffers.

    I did some limited usage test with ehci controller. It seems works for me,
    it did use a bigger buffer and nothing blow up.

    Signed-Off-By: Christopher Li <>

    Index: linux-
    --- linux- 2005-09-28 13:08:10.000000000 -0700
    +++ linux- 2005-10-01 04:58:47.000000000 -0700
    @@ -72,7 +72,7 @@ MODULE_PARM_DESC (usbfs_snoop, "true to
    } while (0)

    -#define MAX_USBFS_BUFFER_SIZE 16384
    +#define MAX_USBFS_BUFFER_SIZE (32*1024)

    static inline int connected (struct usb_device *dev)
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      Last update: 2005-10-02 01:54    [W:0.020 / U:27.068 seconds]
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