From 032de762b44791de7f35c3716046e441c4f2b1a1 Mon Sep 17 00:00:00 2001
From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Fri, 7 Dec 2007 00:03:06 +0000
Subject: [PATCH] [PATCH 1/2] Fix race between device reset and start_xmit
Signed-off-by: oliver@opencloud.com
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@9664 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
target/linux/ar7/files/drivers/net/cpmac.c | 93 ++++++++++++++--------
1 file changed, 61 insertions(+), 32 deletions(-)
diff --git a/target/linux/ar7/files/drivers/net/cpmac.c b/target/linux/ar7/files/drivers/net/cpmac.c
index 2c8d52963..45bd1eeb8 100644
--- a/target/linux/ar7/files/drivers/net/cpmac.c
+++ b/target/linux/ar7/files/drivers/net/cpmac.c
@@ -37,6 +37,7 @@
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <asm/gpio.h>
+#include <asm/atomic.h>
MODULE_AUTHOR("Eugene Konev <ejka@imfi.kspu.ru>");
MODULE_DESCRIPTION("TI AR7 ethernet driver (CPMAC)");
@@ -211,6 +212,7 @@ struct cpmac_priv {
struct net_device *dev;
struct work_struct reset_work;
struct platform_device *pdev;
+ atomic_t reset_pending;
};
static irqreturn_t cpmac_irq(int, void *);
@@ -460,6 +462,9 @@ static int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev)
struct cpmac_desc *desc;
struct cpmac_priv *priv = netdev_priv(dev);
+ if (unlikely(atomic_read(&priv->reset_pending)))
+ return NETDEV_TX_BUSY;
+
if (unlikely(skb_padto(skb, ETH_ZLEN)))
return NETDEV_TX_OK;
@@ -639,14 +644,14 @@ static void cpmac_clear_tx(struct net_device *dev)
priv->desc_ring[i].dataflags = 0;
if (priv->desc_ring[i].skb) {
dev_kfree_skb_any(priv->desc_ring[i].skb);
- if (netif_subqueue_stopped(dev, i))
- netif_wake_subqueue(dev, i);
+ priv->desc_ring[i].skb = NULL;
}
}
}
static void cpmac_hw_error(struct work_struct *work)
{
+ int i;
struct cpmac_priv *priv =
container_of(work, struct cpmac_priv, reset_work);
@@ -655,7 +660,45 @@ static void cpmac_hw_error(struct work_struct *work)
spin_unlock(&priv->rx_lock);
cpmac_clear_tx(priv->dev);
cpmac_hw_start(priv->dev);
- netif_start_queue(priv->dev);
+ barrier();
+ atomic_dec(&priv->reset_pending);
+
+ for (i = 0; i < CPMAC_QUEUES; i++) {
+ netif_wake_subqueue(priv->dev, i);
+ }
+ netif_wake_queue(priv->dev);
+}
+
+static void cpmac_check_status(struct net_device *dev)
+{
+ struct cpmac_priv *priv = netdev_priv(dev);
+
+ u32 macstatus = cpmac_read(priv->regs, CPMAC_MAC_STATUS);
+ int rx_channel = (macstatus >> 8) & 7;
+ int rx_code = (macstatus >> 12) & 15;
+ int tx_channel = (macstatus >> 16) & 7;
+ int tx_code = (macstatus >> 20) & 15;
+
+ if (rx_code || tx_code) {
+ if (netif_msg_drv(priv) && net_ratelimit()) {
+ /* Can't find any documentation on what these error codes actually are.
+ * So just log them and hope..
+ */
+ if (rx_code)
+ printk(KERN_WARNING "%s: host error %d on rx channel %d (macstatus %08x), resetting\n",
+ dev->name, rx_code, rx_channel, macstatus);
+ if (tx_code)
+ printk(KERN_WARNING "%s: host error %d on tx channel %d (macstatus %08x), resetting\n",
+ dev->name, tx_code, tx_channel, macstatus);
+ }
+
+ netif_stop_queue(dev);
+ cpmac_hw_stop(dev);
+ if (schedule_work(&priv->reset_work))
+ atomic_inc(&priv->reset_pending);
+ if (unlikely(netif_msg_hw(priv)))
+ cpmac_dump_regs(dev);
+ }
}
static irqreturn_t cpmac_irq(int irq, void *dev_id)
@@ -687,48 +730,33 @@ static irqreturn_t cpmac_irq(int irq, void *dev_id)
cpmac_write(priv->regs, CPMAC_MAC_EOI_VECTOR, 0);
- if (unlikely(status & (MAC_INT_HOST | MAC_INT_STATUS))) {
- if (netif_msg_drv(priv) && net_ratelimit())
- printk(KERN_ERR "%s: hw error, resetting...\n",
- dev->name);
- netif_stop_queue(dev);
- cpmac_hw_stop(dev);
- schedule_work(&priv->reset_work);
- if (unlikely(netif_msg_hw(priv)))
- cpmac_dump_regs(dev);
- }
+ if (unlikely(status & (MAC_INT_HOST | MAC_INT_STATUS)))
+ cpmac_check_status(dev);
return IRQ_HANDLED;
}
static void cpmac_tx_timeout(struct net_device *dev)
{
- struct cpmac_priv *priv = netdev_priv(dev);
int i;
+ struct cpmac_priv *priv = netdev_priv(dev);
spin_lock(&priv->lock);
dev->stats.tx_errors++;
spin_unlock(&priv->lock);
if (netif_msg_tx_err(priv) && net_ratelimit())
printk(KERN_WARNING "%s: transmit timeout\n", dev->name);
- /*
- * FIXME: waking up random queue is not the best thing to
- * do... on the other hand why we got here at all?
- */
-#ifdef CONFIG_NETDEVICES_MULTIQUEUE
- for (i = 0; i < CPMAC_QUEUES; i++)
- if (priv->desc_ring[i].skb) {
- priv->desc_ring[i].dataflags = 0;
- dev_kfree_skb_any(priv->desc_ring[i].skb);
- netif_wake_subqueue(dev, i);
- break;
- }
-#else
- priv->desc_ring[0].dataflags = 0;
- if (priv->desc_ring[0].skb)
- dev_kfree_skb_any(priv->desc_ring[0].skb);
- netif_wake_queue(dev);
-#endif
+
+ atomic_inc(&priv->reset_pending);
+ barrier();
+ cpmac_clear_tx(dev);
+ barrier();
+ atomic_dec(&priv->reset_pending);
+
+ netif_wake_queue(priv->dev);
+ for (i = 0; i < CPMAC_QUEUES; i++) {
+ netif_wake_subqueue(dev, i);
+ }
}
static int cpmac_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
@@ -924,6 +952,7 @@ static int cpmac_open(struct net_device *dev)
goto fail_irq;
}
+ atomic_set(&priv->reset_pending, 0);
INIT_WORK(&priv->reset_work, cpmac_hw_error);
cpmac_hw_start(dev);
--
2.20.1