Re: what's the state a packet in when a sending complete interrupt happens?
Donald Becker <[email protected]>
| Newsgroups | gmane.linux.drivers.eepro100.devel |
|---|---|
| Message-ID | <[email protected]> |
On Sun, 4 Aug 2002, shigang wrote: > I am doing the overhead analysis for UDP/IP over ethernet. My > testing Network controler is 82559. I meet some problem when I reading > the driver source code (eepro100.c) in Linux kernel 2.2.17 > > I describe the question as follows: > > In function "speedo_start_xmit", If an sending entry's is marked as > CmdIntr, the controler will produce an interrupt when this packet > sending complete. The commend on CmdIntr is "Interrupt after completion", which means after completion of the command. The command is defined as uploading the packet to the Tx FIFO, not finishing the packet transmission,. > My question is what is the means of complete? Is it > means that the packet has been successfully put into the ethernet OR > just be copied from host memory into NIC send buffer? The only indication of most Tx errors or success is the packet counters. The only Tx error reported in real time is a Tx FIFO underrun, which is an erorr transferring the packet to the NIC. -- Donald Becker [email protected] Scyld Computing Corporation http://www.scyld.com 410 Severn Ave. Suite 210 Second Generation Beowulf Clusters Annapolis MD 21403 410-990-9993