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Date: Tue, 12 Jan 2010 06:45:53 -0800
From: Greg KH <greg@kroah.com>
To: Steven Xu <linuxkernel.xxz@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: A QUESTION ABOUT USB DRIVER
Message-ID: <20100112144553.GA26050@kroah.com>
References: <1fd295ee1001102114p1b74336q16bb35d973b40c1c@mail.gmail.com>
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On Mon, Jan 11, 2010 at 01:14:31PM +0800, Steven Xu wrote:
> output: usb 1-1: device descriptor read/64, error -71
> 
> 
> in drivers/usb/core/hub.c  line 2250
> when a udisk inserted run to here
>                         for (j = 0; j < 3; ++j) {
>                                 buf->bMaxPacketSize0 = 0;
> 
>                                 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
>                                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
>                                         USB_DT_DEVICE << 8, 0,
>                                         buf, GET_DESCRIPTOR_BUFSIZE,
>                                         (i ? USB_CTRL_GET_TIMEOUT : 1000));
>  return r=-74,
> 
> WHAT IS THE POSSIBEL REASON FOR THIS?

It is needed, why, are you having problems with it?

thanks,

greg k-h