Re: [PATCH v3 1/1 net-next] net: fec: add napi support to improve proformance
From: Waskiewicz Jr, Peter P <hidden>
Date: 2013-01-25 04:33:13
Also in:
linux-arm-kernel
On Fri, Jan 25, 2013 at 09:29:03AM +0800, Frank Li wrote: [...]
static void
+fec_enet_rx_int_enable(struct net_device *ndev, bool enabled)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ uint int_events;
+
+ int_events = readl(fep->hwp + FEC_IMASK);
+ if (enabled)
+ int_events |= FEC_ENET_RXF;
+ else
+ int_events &= ~FEC_ENET_RXF;
+ writel(int_events, fep->hwp + FEC_IMASK);
+}You hold your hw_lock when this is called to disable the interrupt, but not when you re-enable it. See below. [...]
quoted hunk ↗ jump to hunk
@@ -813,7 +831,14 @@ fec_enet_interrupt(int irq, void *dev_id) if (int_events & FEC_ENET_RXF) { ret = IRQ_HANDLED; - fec_enet_rx(ndev); + + spin_lock(&fep->hw_lock); + /* Disable the RX interrupt */ + if (napi_schedule_prep(&fep->napi)) { + fec_enet_rx_int_enable(ndev, false); + __napi_schedule(&fep->napi); + } + spin_unlock(&fep->hw_lock); } /* Transmit OK, or non-fatal error. Update the buffer@@ -834,7 +859,16 @@ fec_enet_interrupt(int irq, void *dev_id) return ret; } - +static int fec_enet_rx_napi(struct napi_struct *napi, int budget) +{ + struct net_device *ndev = napi->dev; + int pkgs = fec_enet_rx(ndev, budget); + if (pkgs < budget) { + napi_complete(napi); + fec_enet_rx_int_enable(ndev, true);
Here you're not locking when re-enabling, but you do in the disable path. Also, when you're disabling interrupts above, you're doing that in your HW interrupt handler, you should be using spin_lock_irqsave()/irq_restore(). Cheers, -PJ