[PATCH 4/6] forcedeth: Acknowledge only interrupts that are being processed

From: David Decotigny
Date: Wed May 18 2011 - 20:16:32 EST


From: Mike Ditto <mditto@xxxxxxxxxx>

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@xxxxxxxxxx>
---
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 7a6aa08..17e79de 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

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