by support »
Hello,
All link partners must send acknowledges to the packets that arrive. The TLP is guaranteed to arrive (or this is a fundamental bus error, of the sort that crashes the computer).
What the cited sentence says, is that the link partner could be an external switch, so the acknowledgment is just for the first leg. Besides, even if the link partner is a processor, odds are that the acknowledgment is sent before the data has reached the processor's internal bus. There is always some kind of internal bridge, or maybe an internal PCIe switch, that eventually connects with the CPU's main bus (Northbridge or Southbridge, for example).
Regards,
Eli
Hello,
All link partners must send acknowledges to the packets that arrive. The TLP is guaranteed to arrive (or this is a fundamental bus error, of the sort that crashes the computer).
What the cited sentence says, is that the link partner [b]could be[/b] an external switch, so the acknowledgment is just for the first leg. Besides, even if the link partner is a processor, odds are that the acknowledgment is sent before the data has reached the processor's internal bus. There is always some kind of internal bridge, or maybe an internal PCIe switch, that eventually connects with the CPU's main bus (Northbridge or Southbridge, for example).
Regards,
Eli