altera_tse: Fixes in NAPI and interrupt handling paths
Incorrect NAPI polling caused WARNING at net/core/dev.c net_rx_action.
Some stability issues were also seen at high throughput and system
load before this patch.
This patch contains several changes in altera_tse_main.c:
- tse_rx() is fixed to not process more than `limit` frames
- tse_poll() is refactored to match NAPI logic
- only received frames are counted for return value
- removed bogus condition `(rxcomplete >= budget || txcomplete > 0)`
- replace by: if (rxcomplete < budget) -> call __napi_complete and enable irq
- altera_isr()
- replace spin_lock_irqsave() by spin_lock() - we are in isr
- use spinlocks just over irq manipulation, not over __napi_schedule
- reset IRQ first, then disable and schedule napi
This is a cleaned up resubmission from Vlastimil's recent submission.
Signed-off-by: Vlastimil Setka <setka@vsis.cz>
Signed-off-by: Roman Pisl <rpisl@kky.zcu.cz>
Signed-off-by: Vince Bridgers <vbridger@opensource.altera.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/altera/altera_tse_main.c b/drivers/net/ethernet/altera/altera_tse_main.c
index f3d784a..6725dc0 100644
--- a/drivers/net/ethernet/altera/altera_tse_main.c
+++ b/drivers/net/ethernet/altera/altera_tse_main.c
@@ -376,7 +376,8 @@
u16 pktlength;
u16 pktstatus;
- while ((rxstatus = priv->dmaops->get_rx_status(priv)) != 0) {
+ while (((rxstatus = priv->dmaops->get_rx_status(priv)) != 0) &&
+ (count < limit)) {
pktstatus = rxstatus >> 16;
pktlength = rxstatus & 0xffff;
@@ -491,28 +492,27 @@
struct altera_tse_private *priv =
container_of(napi, struct altera_tse_private, napi);
int rxcomplete = 0;
- int txcomplete = 0;
unsigned long int flags;
- txcomplete = tse_tx_complete(priv);
+ tse_tx_complete(priv);
rxcomplete = tse_rx(priv, budget);
- if (rxcomplete >= budget || txcomplete > 0)
- return rxcomplete;
+ if (rxcomplete < budget) {
- napi_gro_flush(napi, false);
- __napi_complete(napi);
+ napi_gro_flush(napi, false);
+ __napi_complete(napi);
- netdev_dbg(priv->dev,
- "NAPI Complete, did %d packets with budget %d\n",
- txcomplete+rxcomplete, budget);
+ netdev_dbg(priv->dev,
+ "NAPI Complete, did %d packets with budget %d\n",
+ rxcomplete, budget);
- spin_lock_irqsave(&priv->rxdma_irq_lock, flags);
- priv->dmaops->enable_rxirq(priv);
- priv->dmaops->enable_txirq(priv);
- spin_unlock_irqrestore(&priv->rxdma_irq_lock, flags);
- return rxcomplete + txcomplete;
+ spin_lock_irqsave(&priv->rxdma_irq_lock, flags);
+ priv->dmaops->enable_rxirq(priv);
+ priv->dmaops->enable_txirq(priv);
+ spin_unlock_irqrestore(&priv->rxdma_irq_lock, flags);
+ }
+ return rxcomplete;
}
/* DMA TX & RX FIFO interrupt routing
@@ -521,7 +521,6 @@
{
struct net_device *dev = dev_id;
struct altera_tse_private *priv;
- unsigned long int flags;
if (unlikely(!dev)) {
pr_err("%s: invalid dev pointer\n", __func__);
@@ -529,20 +528,20 @@
}
priv = netdev_priv(dev);
- /* turn off desc irqs and enable napi rx */
- spin_lock_irqsave(&priv->rxdma_irq_lock, flags);
-
- if (likely(napi_schedule_prep(&priv->napi))) {
- priv->dmaops->disable_rxirq(priv);
- priv->dmaops->disable_txirq(priv);
- __napi_schedule(&priv->napi);
- }
-
+ spin_lock(&priv->rxdma_irq_lock);
/* reset IRQs */
priv->dmaops->clear_rxirq(priv);
priv->dmaops->clear_txirq(priv);
+ spin_unlock(&priv->rxdma_irq_lock);
- spin_unlock_irqrestore(&priv->rxdma_irq_lock, flags);
+ if (likely(napi_schedule_prep(&priv->napi))) {
+ spin_lock(&priv->rxdma_irq_lock);
+ priv->dmaops->disable_rxirq(priv);
+ priv->dmaops->disable_txirq(priv);
+ spin_unlock(&priv->rxdma_irq_lock);
+ __napi_schedule(&priv->napi);
+ }
+
return IRQ_HANDLED;
}
