ftgmac100: Rework NAPI & interrupts handling
First, don't look at the interrupt status in the poll loop to decide what to poll. It's wrong. If we have run out of budget, we may still have RX packets to unqueue but no more RX interrupt pending. So instead move the code looking at the interrupt status into the interrupt handler where it belongs. That avoids a slow MMIO read in the NAPI fast path. We keep the abnormal interrupts enabled while NAPI is scheduled. While at it, actually do something useful in the "error" cases: On AHB bus error, trigger the new reset task, that's about all we can do. On RX packet fifo or descriptor overflows, we need to restart the MAC after having freed things up. So set a flag that NAPI will see and use to perform that restart after harvesting the RX ring. Finally, we shouldn't complete NAPI if there are still outgoing packets that will need harvesting. Waiting for more interrupts is less efficient than letting NAPI run a while longer while the queue drains. Signed-off-by:Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
David S. Miller <davem@davemloft.net>
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