Commit | Line | Data |
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1da177e4 LT |
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 Specified endpoint is stalled. For non-control endpoints, | |
45 | reset this status with usb_clear_halt(). | |
46 | ||
47 | -EMSGSIZE (a) endpoint maxpacket size is zero; it is not usable | |
48 | in the current interface altsetting. | |
49 | (b) ISO packet is biger than endpoint maxpacket | |
50 | (c) requested data transfer size is invalid (negative) | |
51 | ||
52 | -ENOSPC This request would overcommit the usb bandwidth reserved | |
53 | for periodic transfers (interrupt, isochronous). | |
54 | ||
55 | -ESHUTDOWN The device or host controller has been disabled due to some | |
56 | problem that could not be worked around. | |
57 | ||
58 | -EPERM Submission failed because urb->reject was set. | |
59 | ||
60 | -EHOSTUNREACH URB was rejected because the device is suspended. | |
61 | ||
62 | ||
63 | ************************************************************************** | |
64 | * Error codes returned by in urb->status * | |
65 | * or in iso_frame_desc[n].status (for ISO) * | |
66 | ************************************************************************** | |
67 | ||
68 | USB device drivers may only test urb status values in completion handlers. | |
69 | This is because otherwise there would be a race between HCDs updating | |
70 | these values on one CPU, and device drivers testing them on another CPU. | |
71 | ||
72 | A transfer's actual_length may be positive even when an error has been | |
73 | reported. That's because transfers often involve several packets, so that | |
74 | one or more packets could finish before an error stops further endpoint I/O. | |
75 | ||
76 | ||
77 | 0 Transfer completed successfully | |
78 | ||
79 | -ENOENT URB was synchronously unlinked by usb_unlink_urb | |
80 | ||
81 | -EINPROGRESS URB still pending, no results yet | |
82 | (That is, if drivers see this it's a bug.) | |
83 | ||
84 | -EPROTO (*, **) a) bitstuff error | |
85 | b) no response packet received within the | |
86 | prescribed bus turn-around time | |
87 | c) unknown USB error | |
88 | ||
89 | -EILSEQ (*, **) a) CRC mismatch | |
90 | b) no response packet received within the | |
91 | prescribed bus turn-around time | |
92 | c) unknown USB error | |
93 | ||
94 | Note that often the controller hardware does not | |
95 | distinguish among cases a), b), and c), so a | |
96 | driver cannot tell whether there was a protocol | |
97 | error, a failure to respond (often caused by | |
98 | device disconnect), or some other fault. | |
99 | ||
100 | -ETIMEDOUT (**) No response packet received within the prescribed | |
101 | bus turn-around time. This error may instead be | |
102 | reported as -EPROTO or -EILSEQ. | |
103 | ||
104 | Note that the synchronous USB message functions | |
105 | also use this code to indicate timeout expired | |
106 | before the transfer completed. | |
107 | ||
108 | -EPIPE (**) Endpoint stalled. For non-control endpoints, | |
109 | reset this status with usb_clear_halt(). | |
110 | ||
111 | -ECOMM During an IN transfer, the host controller | |
112 | received data from an endpoint faster than it | |
113 | could be written to system memory | |
114 | ||
115 | -ENOSR During an OUT transfer, the host controller | |
116 | could not retrieve data from system memory fast | |
117 | enough to keep up with the USB data rate | |
118 | ||
119 | -EOVERFLOW (*) The amount of data returned by the endpoint was | |
120 | greater than either the max packet size of the | |
121 | endpoint or the remaining buffer size. "Babble". | |
122 | ||
123 | -EREMOTEIO The data read from the endpoint did not fill the | |
124 | specified buffer, and URB_SHORT_NOT_OK was set in | |
125 | urb->transfer_flags. | |
126 | ||
127 | -ENODEV Device was removed. Often preceded by a burst of | |
128 | other errors, since the hub driver does't detect | |
129 | device removal events immediately. | |
130 | ||
131 | -EXDEV ISO transfer only partially completed | |
132 | look at individual frame status for details | |
133 | ||
134 | -EINVAL ISO madness, if this happens: Log off and go home | |
135 | ||
136 | -ECONNRESET URB was asynchronously unlinked by usb_unlink_urb | |
137 | ||
138 | -ESHUTDOWN The device or host controller has been disabled due | |
139 | to some problem that could not be worked around, | |
140 | such as a physical disconnect. | |
141 | ||
142 | ||
143 | (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate | |
144 | hardware problems such as bad devices (including firmware) or cables. | |
145 | ||
146 | (**) This is also one of several codes that different kinds of host | |
147 | controller use to to indicate a transfer has failed because of device | |
148 | disconnect. In the interval before the hub driver starts disconnect | |
149 | processing, devices may receive such fault reports for every request. | |
150 | ||
151 | ||
152 | ||
153 | ************************************************************************** | |
154 | * Error codes returned by usbcore-functions * | |
155 | * (expect also other submit and transfer status codes) * | |
156 | ************************************************************************** | |
157 | ||
158 | usb_register(): | |
159 | -EINVAL error during registering new driver | |
160 | ||
161 | usb_get_*/usb_set_*(): | |
162 | usb_control_msg(): | |
163 | usb_bulk_msg(): | |
164 | -ETIMEDOUT Timeout expired before the transfer completed. | |
165 | In the future this code may change to -ETIME, | |
166 | whose definition is a closer match to this sort | |
167 | of error. |