Linux Kernel Documentation :: usb : error-codes.txt

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Based on kernel version 3.2. Page generated on 2012-01-05 23:29 EST.
1	Revised: 2004-Oct-21
2	
3	This is the documentation of (hopefully) all possible error codes (and
4	their interpretation) that can be returned from usbcore.
5	
6	Some of them are returned by the Host Controller Drivers (HCDs), which
7	device drivers only see through usbcore.  As a rule, all the HCDs should
8	behave the same except for transfer speed dependent behaviors and the
9	way certain faults are reported.
10	
11	
12	**************************************************************************
13	*                   Error codes returned by usb_submit_urb               *
14	**************************************************************************
15	
16	Non-USB-specific:
17	
18	0		URB submission went fine
19	
20	-ENOMEM		no memory for allocation of internal structures	
21	
22	USB-specific:
23	
24	-ENODEV		specified USB-device or bus doesn't exist
25	
26	-ENOENT		specified interface or endpoint does not exist or
27			is not enabled
28	
29	-ENXIO		host controller driver does not support queuing of this type
30			of urb.  (treat as a host controller bug.)
31	
32	-EINVAL		a) Invalid transfer type specified (or not supported)
33			b) Invalid or unsupported periodic transfer interval
34			c) ISO: attempted to change transfer interval
35			d) ISO: number_of_packets is < 0
36			e) various other cases
37	
38	-EAGAIN		a) specified ISO start frame too early
39			b) (using ISO-ASAP) too much scheduled for the future
40			   wait some time and try again.
41	
42	-EFBIG		Host controller driver can't schedule that many ISO frames.
43	
44	-EPIPE		The pipe type specified in the URB doesn't match the
45			endpoint's actual type.
46	
47	-EMSGSIZE	(a) endpoint maxpacket size is zero; it is not usable
48			    in the current interface altsetting.
49			(b) ISO packet is larger than the endpoint maxpacket.
50			(c) requested data transfer length is invalid: negative
51			    or too large for the host controller.
52	
53	-ENOSPC		This request would overcommit the usb bandwidth reserved
54			for periodic transfers (interrupt, isochronous).
55	
56	-ESHUTDOWN	The device or host controller has been disabled due to some
57			problem that could not be worked around.
58	
59	-EPERM		Submission failed because urb->reject was set.
60	
61	-EHOSTUNREACH	URB was rejected because the device is suspended.
62	
63	-ENOEXEC	A control URB doesn't contain a Setup packet.
64	
65	
66	**************************************************************************
67	*                   Error codes returned by in urb->status               *
68	*                   or in iso_frame_desc[n].status (for ISO)             *
69	**************************************************************************
70	
71	USB device drivers may only test urb status values in completion handlers.
72	This is because otherwise there would be a race between HCDs updating
73	these values on one CPU, and device drivers testing them on another CPU.
74	
75	A transfer's actual_length may be positive even when an error has been
76	reported.  That's because transfers often involve several packets, so that
77	one or more packets could finish before an error stops further endpoint I/O.
78	
79	For isochronous URBs, the urb status value is non-zero only if the URB is
80	unlinked, the device is removed, the host controller is disabled, or the total
81	transferred length is less than the requested length and the URB_SHORT_NOT_OK
82	flag is set.  Completion handlers for isochronous URBs should only see
83	urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
84	Individual frame descriptor status fields may report more status codes.
85	
86	
87	0			Transfer completed successfully
88	
89	-ENOENT			URB was synchronously unlinked by usb_unlink_urb
90	
91	-EINPROGRESS		URB still pending, no results yet
92				(That is, if drivers see this it's a bug.)
93	
94	-EPROTO (*, **)		a) bitstuff error
95				b) no response packet received within the
96				   prescribed bus turn-around time
97				c) unknown USB error 
98	
99	-EILSEQ (*, **)		a) CRC mismatch
100				b) no response packet received within the
101				   prescribed bus turn-around time
102				c) unknown USB error 
103	
104				Note that often the controller hardware does not
105				distinguish among cases a), b), and c), so a
106				driver cannot tell whether there was a protocol
107				error, a failure to respond (often caused by
108				device disconnect), or some other fault.
109	
110	-ETIME (**)		No response packet received within the prescribed
111				bus turn-around time.  This error may instead be
112				reported as -EPROTO or -EILSEQ.
113	
114	-ETIMEDOUT		Synchronous USB message functions use this code
115				to indicate timeout expired before the transfer
116				completed, and no other error was reported by HC.
117	
118	-EPIPE (**)		Endpoint stalled.  For non-control endpoints,
119				reset this status with usb_clear_halt().
120	
121	-ECOMM			During an IN transfer, the host controller
122				received data from an endpoint faster than it
123				could be written to system memory
124	
125	-ENOSR			During an OUT transfer, the host controller
126				could not retrieve data from system memory fast
127				enough to keep up with the USB data rate
128	
129	-EOVERFLOW (*)		The amount of data returned by the endpoint was
130				greater than either the max packet size of the
131				endpoint or the remaining buffer size.  "Babble".
132	
133	-EREMOTEIO		The data read from the endpoint did not fill the
134				specified buffer, and URB_SHORT_NOT_OK was set in
135				urb->transfer_flags.
136	
137	-ENODEV			Device was removed.  Often preceded by a burst of
138				other errors, since the hub driver doesn't detect
139				device removal events immediately.
140	
141	-EXDEV			ISO transfer only partially completed
142				(only set in iso_frame_desc[n].status, not urb->status)
143	
144	-EINVAL			ISO madness, if this happens: Log off and go home
145	
146	-ECONNRESET		URB was asynchronously unlinked by usb_unlink_urb
147	
148	-ESHUTDOWN		The device or host controller has been disabled due
149				to some problem that could not be worked around,
150				such as a physical disconnect.
151	
152	
153	(*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
154	hardware problems such as bad devices (including firmware) or cables.
155	
156	(**) This is also one of several codes that different kinds of host
157	controller use to indicate a transfer has failed because of device
158	disconnect.  In the interval before the hub driver starts disconnect
159	processing, devices may receive such fault reports for every request.
160	
161	
162	
163	**************************************************************************
164	*              Error codes returned by usbcore-functions                 *
165	*           (expect also other submit and transfer status codes)         *
166	**************************************************************************
167	
168	usb_register():
169	-EINVAL			error during registering new driver
170	
171	usb_get_*/usb_set_*():
172	usb_control_msg():
173	usb_bulk_msg():
174	-ETIMEDOUT		Timeout expired before the transfer completed.
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