* A QUESTION ABOUT USB DRIVER
@ 2010-01-11 5:14 Steven Xu
2010-01-11 8:25 ` Oliver Neukum
2010-01-12 14:45 ` Greg KH
0 siblings, 2 replies; 3+ messages in thread
From: Steven Xu @ 2010-01-11 5:14 UTC (permalink / raw)
To: linux-kernel
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!
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: A QUESTION ABOUT USB DRIVER
2010-01-11 5:14 A QUESTION ABOUT USB DRIVER Steven Xu
@ 2010-01-11 8:25 ` Oliver Neukum
2010-01-12 14:45 ` Greg KH
1 sibling, 0 replies; 3+ messages in thread
From: Oliver Neukum @ 2010-01-11 8:25 UTC (permalink / raw)
To: Steven Xu, linux-usb; +Cc: linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: A QUESTION ABOUT USB DRIVER
2010-01-11 5:14 A QUESTION ABOUT USB DRIVER Steven Xu
2010-01-11 8:25 ` Oliver Neukum
@ 2010-01-12 14:45 ` Greg KH
1 sibling, 0 replies; 3+ messages in thread
From: Greg KH @ 2010-01-12 14:45 UTC (permalink / raw)
To: Steven Xu; +Cc: linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread
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2010-01-11 8:25 ` Oliver Neukum
2010-01-12 14:45 ` Greg KH
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