[PATCH] forcedeth: Acknowledge only interrupts that are being processed

[PATCH] forcedeth: Acknowledge only interrupts that are being processed

[David Decotigny]

From: Mike Ditto <mditto@google.com>

This is to avoid a race, accidentally acknowledging an interrupt that
we didn't notice and won't immediately process.  This is based solely
on code inspection; it is not known if there was an actual bug here.


Signed-off-by: David Decotigny <decot@google.com>
---
 drivers/net/forcedeth.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 2c176ff..c9bdee6 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -3403,7 +3403,8 @@ static irqreturn_t nv_nic_irq_tx(int foo, void *data)
 
 	for (i = 0;; i++) {
 		events = readl(base + NvRegMSIXIrqStatus) & NVREG_IRQ_TX_ALL;
-		writel(NVREG_IRQ_TX_ALL, base + NvRegMSIXIrqStatus);
+		writel(events, base + NvRegMSIXIrqStatus);
+		netdev_dbg(dev, "%s: tx irq: %08x\n", dev->name, events);
 		if (!(events & np->irqmask))
 			break;
 
@@ -3514,7 +3515,8 @@ static irqreturn_t nv_nic_irq_rx(int foo, void *data)
 
 	for (i = 0;; i++) {
 		events = readl(base + NvRegMSIXIrqStatus) & NVREG_IRQ_RX_ALL;
-		writel(NVREG_IRQ_RX_ALL, base + NvRegMSIXIrqStatus);
+		writel(events, base + NvRegMSIXIrqStatus);
+		netdev_dbg(dev, "%s: rx irq: %08x\n", dev->name, events);
 		if (!(events & np->irqmask))
 			break;
 
@@ -3558,7 +3560,8 @@ static irqreturn_t nv_nic_irq_other(int foo, void *data)
 
 	for (i = 0;; i++) {
 		events = readl(base + NvRegMSIXIrqStatus) & NVREG_IRQ_OTHER;
-		writel(NVREG_IRQ_OTHER, base + NvRegMSIXIrqStatus);
+		writel(events, base + NvRegMSIXIrqStatus);
+		netdev_dbg(dev, "%s: irq: %08x\n", dev->name, events);
 		if (!(events & np->irqmask))
 			break;
 
@@ -3622,10 +3625,10 @@ static irqreturn_t nv_nic_irq_test(int foo, void *data)
 
 	if (!(np->msi_flags & NV_MSI_X_ENABLED)) {
 		events = readl(base + NvRegIrqStatus) & NVREG_IRQSTAT_MASK;
-		writel(NVREG_IRQ_TIMER, base + NvRegIrqStatus);
+		writel(events & NVREG_IRQ_TIMER, base + NvRegIrqStatus);
 	} else {
 		events = readl(base + NvRegMSIXIrqStatus) & NVREG_IRQSTAT_MASK;
-		writel(NVREG_IRQ_TIMER, base + NvRegMSIXIrqStatus);
+		writel(events & NVREG_IRQ_TIMER, base + NvRegMSIXIrqStatus);
 	}
 	pci_push(base);
 	if (!(events & NVREG_IRQ_TIMER))
-- 
1.7.3.1

[PATCH] forcedeth: Add messages to indicate using MSI or MSI-X

[David Decotigny]

From: Mike Ditto <mditto@google.com>

This adds a few debug messages to indicate whether PCIe interrupts are
signaled with MSI or MSI-X.


Signed-off-by: David Decotigny <decot@google.com>
---
 drivers/net/forcedeth.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index c9bdee6..e5c5849 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -3745,6 +3745,7 @@ static int nv_request_irq(struct net_device *dev, int intr_test)
 				writel(0, base + NvRegMSIXMap0);
 				writel(0, base + NvRegMSIXMap1);
 			}
+			netdev_info(dev, "forcedeth: MSI-X enabled\n");
 		}
 	}
 	if (ret != 0 && np->msi_flags & NV_MSI_CAPABLE) {
@@ -3766,6 +3767,7 @@ static int nv_request_irq(struct net_device *dev, int intr_test)
 			writel(0, base + NvRegMSIMap1);
 			/* enable msi vector 0 */
 			writel(NVREG_MSI_VECTOR_0_ENABLED, base + NvRegMSIIrqMask);
+			netdev_info(dev, "forcedeth: MSI enabled\n");
 		}
 	}
 	if (ret != 0) {
-- 
1.7.3.1

[PATCH] forcedeth: Fix a race during rmmod of forcedeth

[David Decotigny]

From: Salman Qazi <sqazi@google.com>

The race was between del_timer_sync and nv_do_stats_poll called through
nv_get_ethtool_stats.  To prevent this, we have to introduce mutual
exclusion between nv_get_ethtool_stats and del_timer_sync.  Notice
that we don't put the mutual exclusion in nv_do_stats_poll.  That's
because doing so would result in a deadlock, since it is a timer
callback and hence already waited for by timer deletion.


Signed-off-by: David Decotigny <decot@google.com>
---
 drivers/net/forcedeth.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index e5c5849..3163a2b 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -3921,6 +3921,10 @@ static void nv_poll_controller(struct net_device *dev)
 }
 #endif
 
+/* No locking is needed as long as this is in the timer
+ * callback.  However, any other callers must call this
+ * function with np->lock held.
+ */
 static void nv_do_stats_poll(unsigned long data)
 {
 	struct net_device *dev = (struct net_device *) data;
@@ -4553,12 +4557,17 @@ static int nv_get_sset_count(struct net_device *dev, int sset)
 
 static void nv_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *estats, u64 *buffer)
 {
+	unsigned long flags;
 	struct fe_priv *np = netdev_priv(dev);
 
+	spin_lock_irqsave(&np->lock, flags);
+
 	/* update stats */
 	nv_do_stats_poll((unsigned long)dev);
 
 	memcpy(buffer, &np->estats, nv_get_sset_count(dev, ETH_SS_STATS)*sizeof(u64));
+
+	spin_unlock_irqrestore(&np->lock, flags);
 }
 
 static int nv_link_test(struct net_device *dev)
@@ -5176,13 +5185,13 @@ static int nv_close(struct net_device *dev)
 
 	spin_lock_irq(&np->lock);
 	np->in_shutdown = 1;
+	del_timer_sync(&np->stats_poll);
 	spin_unlock_irq(&np->lock);
 	nv_napi_disable(dev);
 	synchronize_irq(np->pci_dev->irq);
 
 	del_timer_sync(&np->oom_kick);
 	del_timer_sync(&np->nic_poll);
-	del_timer_sync(&np->stats_poll);
 
 	netif_stop_queue(dev);
 	spin_lock_irq(&np->lock);
-- 
1.7.3.1