diff options
Diffstat (limited to 'drivers/net/ethernet/cadence/macb_main.c')
| -rw-r--r-- | drivers/net/ethernet/cadence/macb_main.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 98498a76ae16..d13f06cf0308 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -1573,7 +1573,14 @@ static int macb_poll(struct napi_struct *napi, int budget) if (work_done < budget) { napi_complete_done(napi, work_done); - /* Packets received while interrupts were disabled */ + /* RSR bits only seem to propagate to raise interrupts when + * interrupts are enabled at the time, so if bits are already + * set due to packets received while interrupts were disabled, + * they will not cause another interrupt to be generated when + * interrupts are re-enabled. + * Check for this case here. This has been seen to happen + * around 30% of the time under heavy network load. + */ status = macb_readl(bp, RSR); if (status) { if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE) @@ -1581,6 +1588,22 @@ static int macb_poll(struct napi_struct *napi, int budget) napi_reschedule(napi); } else { queue_writel(queue, IER, bp->rx_intr_mask); + + /* In rare cases, packets could have been received in + * the window between the check above and re-enabling + * interrupts. Therefore, a double-check is required + * to avoid losing a wakeup. This can potentially race + * with the interrupt handler doing the same actions + * if an interrupt is raised just after enabling them, + * but this should be harmless. + */ + status = macb_readl(bp, RSR); + if (unlikely(status)) { + queue_writel(queue, IDR, bp->rx_intr_mask); + if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE) + queue_writel(queue, ISR, MACB_BIT(RCOMP)); + napi_schedule(napi); + } } } |