BSP Developer's Guide

VxWorks 5.5
BSP Developer’s Guide
}
pMblk->mBlkHdr.mData,
pMblk->mBlkHdr.mLen);
Step 6:
Take special care to ensure that all failure conditions be properly logged.
The RFC 2233 interface provides the routine m2IfCounterUpdate( ) to maintain
the various counters relevant for failure conditions. All failure conditions are
considered errors. However, there are two general classes of failure conditions. The
device can return an error status either because of failure to accomplish a requested
action, or because of the driver’s inability to handle a packet due to a lack of
available resources.
Device failure conditions can be further categorized into errors-only and
errors-with-discards, based on whether the failure causes packets to be dropped or
not. If no packet is dropped, the failure is only an error; if data is dropped, the
failure is both an error and a discard. Most device errors are both.
If the driver receives a packet that was corrupted at receipt, this constitutes an error
only. However, if a driver is unable to handle a perfectly good packet due to a lack
of resources, this is always both an error and a discard.
The RFC 2233 interface maintains counters for both incoming and outgoing errors
and discards. The API provides selection by providing corresponding flags that
designate each particular counter. This flag is passed as the second argument to
m2IfCounterUpdate( ).
The relevant flags are:
M2_ctrId_ifInDiscards
M2_ctrId_ifInErrors
M2_ctrId_ifOutDiscards
M2_ctrId_ifOutErrors
For example:
/* New RFC 2233 mib2 interface */
if (pDrvCtrl->endObj.pMib2Tbl != NULL)
{
pDrvCtrl->endObj.pMib2Tbl->m2CtrUpdateRtn(pDrvCtrl->endObj.pMib2Tbl,
M2_ctrId_ifInErrors, 1);
pDrvCtrl->endObj.pMib2Tbl->m2CtrUpdateRtn(pDrvCtrl->endObj.pMib2Tbl,
M2_ctrId_ifInDiscards, 1);
}
316