From: Oliver Neukum <oliver@neukum.org>
To: Steven Xu <linuxkernel.xxz@gmail.com>, linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: Re: A QUESTION ABOUT USB DRIVER
Date: Mon, 11 Jan 2010 09:25:53 +0100 [thread overview]
Message-ID: <201001110925.53711.oliver@neukum.org> (raw)
In-Reply-To: <1fd295ee1001102114p1b74336q16bb35d973b40c1c@mail.gmail.com>
Am Montag, 11. Januar 2010 06:14:31 schrieb Steven Xu:
> 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?
> THANKS!
This is -EPROTO. It means that a low level error on the wire happened,
for example a device sent a malformed package. This is a very unspecific
error.
HTH
Oliver
next prev parent reply other threads:[~2010-01-11 8:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-11 5:14 A QUESTION ABOUT USB DRIVER Steven Xu
2010-01-11 8:25 ` Oliver Neukum [this message]
2010-01-12 14:45 ` Greg KH
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