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+ DSP/Bridge Error Code Guide
+
+
+Success code is always taken as 0, except for one case where a success status
+different than 0 can be possible, this is when enumerating a series of dsp
+objects, if the enumeration doesn't have any more objects it is considered as a
+successful case. In this case a positive ENODATA is returned (TODO: Change to
+avoid this case).
+
+Error codes are returned as a negative 1, if an specific code is expected, it
+can be propagated to user space by reading errno symbol defined in errno.h, for
+specific details on the implementation a copy of the standard used should be
+read first.
+
+The error codes used by this driver are:
+
+[EPERM]
+ General driver failure.
+
+ According to the use case the following might apply:
+ - Device is in 'sleep/suspend' mode due to DPM.
+ - User cannot mark end of stream on an input channel.
+ - Requested operation is invalid for the node type.
+ - Invalid alignment for the node messaging buffer.
+ - The specified direction is invalid for the stream.
+ - Invalid stream mode.
+
+[ENOENT]
+ The specified object or file was not found.
+
+[ESRCH]
+ A shared memory buffer contained in a message or stream could not be mapped
+ to the GPP client process's virtual space.
+
+[EIO]
+ Driver interface I/O error.
+
+ or:
+ - Unable to plug channel ISR for configured IRQ.
+ - No free I/O request packets are available.
+
+[ENXIO]
+ Unable to find a named section in DSP executable or a non-existent memory
+ segment identifier was specified.
+
+[EBADF]
+ General error for file handling:
+
+ - Unable to open file.
+ - Unable to read file.
+ - An error occurred while parsing the DSP executable file.
+
+[ENOMEM]
+ A memory allocation failure occurred.
+
+[EACCES]
+ - Unable to read content of DCD data section; this is typically caused by
+ improperly configured nodes.
+ - Unable to decode DCD data section content; this is typically caused by
+ changes to DSP/BIOS Bridge data structures.
+ - Unable to get pointer to DCD data section; this is typically caused by
+ improperly configured UUIDs.
+ - Unable to load file containing DCD data section; this is typically
+ caused by a missing COFF file.
+ - The specified COFF file does not contain a valid node registration
+ section.
+
+[EFAULT]
+ Invalid pointer or handler.
+
+[EEXIST]
+ Attempted to create a channel manager when one already exists.
+
+[EINVAL]
+ Invalid argument.
+
+[ESPIPE]
+ Symbol not found in the COFF file. DSPNode_Create will return this if
+ the iAlg function table for an xDAIS socket is not found in the COFF file.
+ In this case, force the symbol to be linked into the COFF file.
+ DSPNode_Create, DSPNode_Execute, and DSPNode_Delete will return this if
+ the create, execute, or delete phase function, respectively, could not be
+ found in the COFF file.
+
+ - No symbol table is loaded/found for this board.
+ - Unable to initialize the ZL COFF parsing module.
+
+[EPIPE]
+ I/O is currently pending.
+
+ - End of stream was already requested on this output channel.
+
+[EDOM]
+ A parameter is specified outside its valid range.
+
+[ENOSYS]
+ The indicated operation is not supported.
+
+[EIDRM]
+ During enumeration a change in the number or properties of the objects
+ has occurred.
+
+[ECHRNG]
+ Attempt to created channel manager with too many channels or channel ID out
+ of range.
+
+[EBADR]
+ The state of the specified object is incorrect for the requested operation.
+
+ - Invalid segment ID.
+
+[ENODATA]
+ Unable to retrieve resource information from the registry.
+
+ - No more registry values.
+
+[ETIME]
+ A timeout occurred before the requested operation could complete.
+
+[ENOSR]
+ A stream has been issued the maximum number of buffers allowed in the
+ stream at once; buffers must be reclaimed from the stream before any more
+ can be issued.
+
+ - No free channels are available.
+
+[EILSEQ]
+ Error occurred in a dynamic loader library function.
+
+[EISCONN]
+ The Specified Connection already exists.
+
+[ENOTCONN]
+ Nodes not connected.
+
+[ETIMEDOUT]
+ Timeout occurred waiting for a response from the hardware.
+
+ - Wait for flush operation on an output channel timed out.
+
+[ECONNREFUSED]
+ No more connections can be made for this node.
+
+[EALREADY]
+ Channel is already in use.
+
+[EREMOTEIO]
+ dwTimeOut parameter was CHNL_IOCNOWAIT, yet no I/O completions were
+ queued.
+
+[ECANCELED]
+ I/O has been cancelled on this channel.
+
+[ENOKEY]
+ Invalid subkey parameter.
+
+ - UUID not found in registry.