[PATCH net v3 2/9] forcedeth: Acknowledge only interrupts that are being processed

From: David Decotigny
Date: Fri Nov 04 2011 - 21:55:12 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 <david.decotigny@xxxxxxxxxx>
---
drivers/net/ethernet/nvidia/forcedeth.c | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index 2f884fc..9aefee1 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -3398,7 +3398,8 @@ 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, "tx irq events: %08x\n", events);
if (!(events & np->irqmask))
break;

@@ -3509,7 +3510,8 @@ 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, "rx irq events: %08x\n", events);
if (!(events & np->irqmask))
break;

@@ -3553,7 +3555,8 @@ 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, "irq events: %08x\n", events);
if (!(events & np->irqmask))
break;

@@ -3617,10 +3620,10 @@ 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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