This document describe some USB core features. Add it to the
driver-api book.
Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
---
Documentation/driver-api/usb/error-codes.rst | 205 +++++++++++++++++++++++++++
Documentation/driver-api/usb/index.rst | 1 +
Documentation/usb/error-codes.txt | 175 -----------------------
3 files changed, 206 insertions(+), 175 deletions(-)
create mode 100644 Documentation/driver-api/usb/error-codes.rst
delete mode 100644 Documentation/usb/error-codes.txt
diff --git a/Documentation/driver-api/usb/error-codes.rst
b/Documentation/driver-api/usb/error-codes.rst
new file mode 100644
index 000000000000..715cc35b29b0
--- /dev/null
+++ b/Documentation/driver-api/usb/error-codes.rst
@@ -0,0 +1,205 @@
+USB Error codes
+~~~~~~~~~~~~~~~
+
+Revised: 2004-Oct-21
+
+This is the documentation of (hopefully) all possible error codes (and
+their interpretation) that can be returned from usbcore.
+
+Some of them are returned by the Host Controller Drivers (HCDs), which
+device drivers only see through usbcore. As a rule, all the HCDs should
+behave the same except for transfer speed dependent behaviors and the
+way certain faults are reported.
+
+
+Error codes returned by :c:func:`usb_submit_urb`
+================================================
+
+Non-USB-specific:
+
+
+=============== ===============================================
+0 URB submission went fine
+
+``-ENOMEM`` no memory for allocation of internal structures
+=============== ===============================================
+
+USB-specific:
+
+=======================
=======================================================
+``-EBUSY`` The URB is already active.
+
+``-ENODEV`` specified USB-device or bus doesn't exist
+
+``-ENOENT`` specified interface or endpoint does not exist or
+ is not enabled
+
+``-ENXIO`` host controller driver does not support queuing of
+ this type of urb. (treat as a host controller bug.)
+
+``-EINVAL`` a) Invalid transfer type specified (or not supported)
+ b) Invalid or unsupported periodic transfer interval
+ c) ISO: attempted to change transfer interval
+ d) ISO: ``number_of_packets`` is < 0
+ e) various other cases
+
+``-EXDEV`` ISO: ``URB_ISO_ASAP`` wasn't specified and all the
+ frames the URB would be scheduled in have already
+ expired.
+
+``-EFBIG`` Host controller driver can't schedule that many ISO
+ frames.
+
+``-EPIPE`` The pipe type specified in the URB doesn't match the
+ endpoint's actual type.
+
+``-EMSGSIZE`` (a) endpoint maxpacket size is zero; it is not usable
+ in the current interface altsetting.
+ (b) ISO packet is larger than the endpoint maxpacket.
+ (c) requested data transfer length is invalid: negative
+ or too large for the host controller.
+
+``-ENOSPC`` This request would overcommit the usb bandwidth reserved
+ for periodic transfers (interrupt, isochronous).
+
+``-ESHUTDOWN`` The device or host controller has been disabled due to
+ some problem that could not be worked around.
+
+``-EPERM`` Submission failed because ``urb->reject`` was set.
+
+``-EHOSTUNREACH`` URB was rejected because the device is suspended.
+
+``-ENOEXEC`` A control URB doesn't contain a Setup packet.
+=======================
=======================================================
+
+Error codes returned by ``in urb->status`` or in ``iso_frame_desc[n].status``
(for ISO)
+=======================================================================================
+
+USB device drivers may only test urb status values in completion handlers.
+This is because otherwise there would be a race between HCDs updating
+these values on one CPU, and device drivers testing them on another CPU.
+
+A transfer's actual_length may be positive even when an error has been
+reported. That's because transfers often involve several packets, so that
+one or more packets could finish before an error stops further endpoint I/O.
+
+For isochronous URBs, the urb status value is non-zero only if the URB is
+unlinked, the device is removed, the host controller is disabled, or the total
+transferred length is less than the requested length and the
+``URB_SHORT_NOT_OK`` flag is set. Completion handlers for isochronous URBs
+should only see ``urb->status`` set to zero, ``-ENOENT``, ``-ECONNRESET``,
+``-ESHUTDOWN``, or ``-EREMOTEIO``. Individual frame descriptor status fields
+may report more status codes.
+
+
+===============================
===============================================
+0 Transfer completed successfully
+
+``-ENOENT`` URB was synchronously unlinked by
+ :c:func:`usb_unlink_urb`
+
+``-EINPROGRESS`` URB still pending, no results yet
+ (That is, if drivers see this it's a bug.)
+
+``-EPROTO`` [#f1]_, [#f2]_ a) bitstuff error
+ b) no response packet received within the
+ prescribed bus turn-around time
+ c) unknown USB error
+
+``-EILSEQ`` [#f1]_, [#f2]_ a) CRC mismatch
+ b) no response packet received within the
+ prescribed bus turn-around time
+ c) unknown USB error
+
+ Note that often the controller hardware does
+ not distinguish among cases a), b), and c), so
+ a driver cannot tell whether there was a
+ protocol error, a failure to respond (often
+ caused by device disconnect), or some other
+ fault.
+
+``-ETIME`` [#f2]_ No response packet received within the
+ prescribed bus turn-around time. This error
+ may instead be reported as
+ ``-EPROTO`` or ``-EILSEQ``.
+
+``-ETIMEDOUT`` Synchronous USB message functions use this code
+ to indicate timeout expired before the transfer
+ completed, and no other error was reported
+ by HC.
+
+``-EPIPE`` [#f2]_ Endpoint stalled. For non-control endpoints,
+ reset this status with
+ :c:func:`usb_clear_halt`.
+
+``-ECOMM`` During an IN transfer, the host controller
+ received data from an endpoint faster than it
+ could be written to system memory
+
+``-ENOSR`` During an OUT transfer, the host controller
+ could not retrieve data from system memory fast
+ enough to keep up with the USB data rate
+
+``-EOVERFLOW`` [#f1]_ The amount of data returned by the endpoint was
+ greater than either the max packet size of the
+ endpoint or the remaining buffer size.
+ "Babble".
+
+``-EREMOTEIO`` The data read from the endpoint did not fill
+ the specified buffer, and ``URB_SHORT_NOT_OK``
+ was set in ``urb->transfer_flags``.
+
+``-ENODEV`` Device was removed. Often preceded by a burst
+ of other errors, since the hub driver doesn't
+ detect device removal events immediately.
+
+``-EXDEV`` ISO transfer only partially completed
+ (only set in ``iso_frame_desc[n].status``,
+ not ``urb->status``)
+
+``-EINVAL`` ISO madness, if this happens: Log off and
+ go home
+
+``-ECONNRESET`` URB was asynchronously unlinked by
+ :c:func:`usb_unlink_urb`
+
+``-ESHUTDOWN`` The device or host controller has been
+ disabled due to some problem that could not
+ be worked around, such as a physical
+ disconnect.
+===============================
===============================================
+
+
+.. [#f1]
+
+ Error codes like ``-EPROTO``, ``-EILSEQ`` and ``-EOVERFLOW`` normally
+ indicate hardware problems such as bad devices (including firmware)
+ or cables.
+
+.. [#f2]
+
+ This is also one of several codes that different kinds of host
+ controller use to indicate a transfer has failed because of device
+ disconnect. In the interval before the hub driver starts disconnect
+ processing, devices may receive such fault reports for every request.
+
+
+
+Error codes returned by usbcore-functions
+=========================================
+
+.. note:: expect also other submit and transfer status codes
+
+:c:func:`usb_register`:
+
+======================= ===================================
+``-EINVAL`` error during registering new driver
+======================= ===================================
+
+``usb_get_*/usb_set_*()``,
+:c:func:`usb_control_msg`,
+:c:func:`usb_bulk_msg()`:
+
+======================= ==============================================
+``-ETIMEDOUT`` Timeout expired before the transfer completed.
+======================= ==============================================
diff --git a/Documentation/driver-api/usb/index.rst
b/Documentation/driver-api/usb/index.rst
index d7610777784b..1e2a0c54eb3d 100644
--- a/Documentation/driver-api/usb/index.rst
+++ b/Documentation/driver-api/usb/index.rst
@@ -11,6 +11,7 @@ Linux USB API
callbacks
dma
power-management
+ error-codes
writing_usb_driver
writing_musb_glue_layer
diff --git a/Documentation/usb/error-codes.txt
b/Documentation/usb/error-codes.txt
deleted file mode 100644
index 9c3eb845ebe5..000000000000
--- a/Documentation/usb/error-codes.txt
+++ /dev/null
@@ -1,175 +0,0 @@
-Revised: 2004-Oct-21
-
-This is the documentation of (hopefully) all possible error codes (and
-their interpretation) that can be returned from usbcore.
-
-Some of them are returned by the Host Controller Drivers (HCDs), which
-device drivers only see through usbcore. As a rule, all the HCDs should
-behave the same except for transfer speed dependent behaviors and the
-way certain faults are reported.
-
-
-**************************************************************************
-* Error codes returned by usb_submit_urb *
-**************************************************************************
-
-Non-USB-specific:
-
-0 URB submission went fine
-
--ENOMEM no memory for allocation of internal structures
-
-USB-specific:
-
--EBUSY The URB is already active.
-
--ENODEV specified USB-device or bus doesn't exist
-
--ENOENT specified interface or endpoint does not exist or
- is not enabled
-
--ENXIO host controller driver does not support queuing of this type
- of urb. (treat as a host controller bug.)
-
--EINVAL a) Invalid transfer type specified (or not supported)
- b) Invalid or unsupported periodic transfer interval
- c) ISO: attempted to change transfer interval
- d) ISO: number_of_packets is < 0
- e) various other cases
-
--EXDEV ISO: URB_ISO_ASAP wasn't specified and all the frames
- the URB would be scheduled in have already expired.
-
--EFBIG Host controller driver can't schedule that many ISO frames.
-
--EPIPE The pipe type specified in the URB doesn't match the
- endpoint's actual type.
-
--EMSGSIZE (a) endpoint maxpacket size is zero; it is not usable
- in the current interface altsetting.
- (b) ISO packet is larger than the endpoint maxpacket.
- (c) requested data transfer length is invalid: negative
- or too large for the host controller.
-
--ENOSPC This request would overcommit the usb bandwidth reserved
- for periodic transfers (interrupt, isochronous).
-
--ESHUTDOWN The device or host controller has been disabled due to some
- problem that could not be worked around.
-
--EPERM Submission failed because urb->reject was set.
-
--EHOSTUNREACH URB was rejected because the device is suspended.
-
--ENOEXEC A control URB doesn't contain a Setup packet.
-
-
-**************************************************************************
-* Error codes returned by in urb->status *
-* or in iso_frame_desc[n].status (for ISO) *
-**************************************************************************
-
-USB device drivers may only test urb status values in completion handlers.
-This is because otherwise there would be a race between HCDs updating
-these values on one CPU, and device drivers testing them on another CPU.
-
-A transfer's actual_length may be positive even when an error has been
-reported. That's because transfers often involve several packets, so that
-one or more packets could finish before an error stops further endpoint I/O.
-
-For isochronous URBs, the urb status value is non-zero only if the URB is
-unlinked, the device is removed, the host controller is disabled, or the total
-transferred length is less than the requested length and the URB_SHORT_NOT_OK
-flag is set. Completion handlers for isochronous URBs should only see
-urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
-Individual frame descriptor status fields may report more status codes.
-
-
-0 Transfer completed successfully
-
--ENOENT URB was synchronously unlinked by usb_unlink_urb
-
--EINPROGRESS URB still pending, no results yet
- (That is, if drivers see this it's a bug.)
-
--EPROTO (*, **) a) bitstuff error
- b) no response packet received within the
- prescribed bus turn-around time
- c) unknown USB error
-
--EILSEQ (*, **) a) CRC mismatch
- b) no response packet received within the
- prescribed bus turn-around time
- c) unknown USB error
-
- Note that often the controller hardware does not
- distinguish among cases a), b), and c), so a
- driver cannot tell whether there was a protocol
- error, a failure to respond (often caused by
- device disconnect), or some other fault.
-
--ETIME (**) No response packet received within the prescribed
- bus turn-around time. This error may instead be
- reported as -EPROTO or -EILSEQ.
-
--ETIMEDOUT Synchronous USB message functions use this code
- to indicate timeout expired before the transfer
- completed, and no other error was reported by HC.
-
--EPIPE (**) Endpoint stalled. For non-control endpoints,
- reset this status with usb_clear_halt().
-
--ECOMM During an IN transfer, the host controller
- received data from an endpoint faster than it
- could be written to system memory
-
--ENOSR During an OUT transfer, the host controller
- could not retrieve data from system memory fast
- enough to keep up with the USB data rate
-
--EOVERFLOW (*) The amount of data returned by the endpoint was
- greater than either the max packet size of the
- endpoint or the remaining buffer size. "Babble".
-
--EREMOTEIO The data read from the endpoint did not fill the
- specified buffer, and URB_SHORT_NOT_OK was set in
- urb->transfer_flags.
-
--ENODEV Device was removed. Often preceded by a burst
of
- other errors, since the hub driver doesn't detect
- device removal events immediately.
-
--EXDEV ISO transfer only partially completed
- (only set in iso_frame_desc[n].status, not urb->status)
-
--EINVAL ISO madness, if this happens: Log off and go
home
-
--ECONNRESET URB was asynchronously unlinked by usb_unlink_urb
-
--ESHUTDOWN The device or host controller has been disabled due
- to some problem that could not be worked around,
- such as a physical disconnect.
-
-
-(*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
-hardware problems such as bad devices (including firmware) or cables.
-
-(**) This is also one of several codes that different kinds of host
-controller use to indicate a transfer has failed because of device
-disconnect. In the interval before the hub driver starts disconnect
-processing, devices may receive such fault reports for every request.
-
-
-
-**************************************************************************
-* Error codes returned by usbcore-functions *
-* (expect also other submit and transfer status codes) *
-**************************************************************************
-
-usb_register():
--EINVAL error during registering new driver
-
-usb_get_*/usb_set_*():
-usb_control_msg():
-usb_bulk_msg():
--ETIMEDOUT Timeout expired before the transfer completed.
--
2.9.3
--
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