Kernel Functions for Drivers               ddifmaccerrget(9F)



NAME
     ddifmaccerrget,  ddifmdmaerrget  -  get  the   error
     status for an access or DMA handle

SYNOPSIS
     #include 

     void ddifmaccerrget(ddiacchandlet acchandle,
          ddifmerrort *errorstatus, int version);


     void ddifmdmaerrget(ddidmahandlet dmahandle,
          ddifmerrort *errorstatus, int version);


INTERFACE LEVEL
     Solaris DI specific (Solaris DI)

PARAMETERS
     acchandle      Data access handle obtained from a  previous
                     call        to       ddiregsmapsetup(9F),
                     ddidmamemalloc(9F), or to a similar func-
                     tion.


     dmahandle      DMA handle obtained from a previous call  to
                     ddidmamemalloc(9F)  or one of its deriva-
                     tives.


     errorstatus    Pointer to where the error  status  for  the
                     access or DMA handle should be returned.


     version         Version number of ddifmerrort. The driver
                     should always set this to DIFMEVERSION.


DESCRIPTION
     The ddifmdmaerrget() and ddifmaccerrget()  functions
     return  the  error status for a DMA or access handle respec-
     tively. If a fault has occurred that  affects  the  resource
     mapped  by  the  supplied  handle, the supplied errorstatus
     structure is updated to reflect error  information  captured
     during error handling by a bus or other device driver in the
     I/O data path.


     If an error is indicated for an access  handle,  the  driver
     might  no  longer  be able to access the mapped registers or
     memory using programmed I/O through the  handle.  Typically,
     this  might  occur after the device has failed to respond to



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Kernel Functions for Drivers               ddifmaccerrget(9F)



     an I/O access - in the case of a bus error, for instance, or
     a  timeout.  The effect of programmed I/O access made at the
     time of a fault is undefined. Read access via  ddiget8(9F),
     for  example,  can  return random values, while write access
     via ddiput8(9F) might or might not have an  effect.  It  is
     possible,  however,  that  the  error might be transient. In
     that case, the driver can  attempt  to  recover  by  calling
     ddifmaccerrclear(), resetting the device to return it to
     a known state, then retrying any potentially failed transac-
     tions.


     If an error is indicated for a DMA handle, it  implies  that
     an error has been detected that has or will affect DMA tran-
     sactions between the device and the memory  currently  bound
     to  the  handle  - or the memory most recently bound, if the
     handle is currently unbound.  Possible  causes  include  the
     failure of a component in the DMA data path or an attempt by
     the device to make an invalid DMA access.  The  contents  of
     any  memory  currently  or  previously  bound  to the handle
     should be considered indeterminate. The driver might be able
     to  continue  by  freeing memory that is bound to the handle
     back to the system, resetting the device to return it  to  a
     known  state,  then retrying any potentially failed transac-
     tions.


     If the driver is unable  to  recover,  the  operating  state
     should  be changed by a call to ddifmserviceimpact() that
     specifies DISERVICELOST for the impacted device instance.
     If  the  recovery  and retry succeed, a call should still be
     made to ddifmserviceimpact()  but  DISERVICEUNAFECTED
     should be specified.

CONTEXT
     The ddifmaccerrget() and ddifmdmaerrget()  functions
     can  be  called  from  user, kernel, or high-level interrupt
     context.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:













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Kernel Functions for Drivers               ddifmaccerrget(9F)



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Committed                   
    


SEE ALSO
     attributes(5),                        ddidmamemalloc(9F),
     ddifmaccerrclear(9F),         ddifmserviceimpact(9F),
     ddiget8(9F),     ddiput8(9F),      ddiregsmapsetup(9F),
     ddifmerror(9S),


     Writing Device Drivers








































SunOS 5.11          Last change: 13 May 2007                    3