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forcedeth: fix irq clearing and napi spin lock changes

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This patch clears the irqstatus register with the exact same events it
has read from it. Since the read-write operation is not atomic, a new
irqstatus bit could have been set in between these operations and would
then be cleared accidentally.

Secondly, we now don't need any spin lock protection when
scheduling/completing napi poll as the isr will not execute anymore (as
we turn off all interrupts now).

Signed-off-by: Ayaz Abdulla <aabdulla@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ayaz Abdulla
2009-03-05 08:02:34 +00:00
committed by David S. Miller
parent 6cef67a02f
commit 1b2bb76f57
1 changed files with 4 additions and 14 deletions
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18
drivers/net/forcedeth.c
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@@ -3464,10 +3464,10 @@ static irqreturn_t nv_nic_irq(int foo, void *data)
if (!(np->msi_flags & NV_MSI_X_ENABLED)) { if (!(np->msi_flags & NV_MSI_X_ENABLED)) {
np->events = readl(base + NvRegIrqStatus); np->events = readl(base + NvRegIrqStatus);
writel(NVREG_IRQSTAT_MASK, base + NvRegIrqStatus); writel(np->events, base + NvRegIrqStatus);
} else { } else {
np->events = readl(base + NvRegMSIXIrqStatus); np->events = readl(base + NvRegMSIXIrqStatus);
writel(NVREG_IRQSTAT_MASK, base + NvRegMSIXIrqStatus); writel(np->events, base + NvRegMSIXIrqStatus);
} }
dprintk(KERN_DEBUG "%s: irq: %08x\n", dev->name, np->events); dprintk(KERN_DEBUG "%s: irq: %08x\n", dev->name, np->events);
if (!(np->events & np->irqmask)) if (!(np->events & np->irqmask))
@@ -3476,15 +3476,12 @@ static irqreturn_t nv_nic_irq(int foo, void *data)
nv_msi_workaround(np); nv_msi_workaround(np);
#ifdef CONFIG_FORCEDETH_NAPI #ifdef CONFIG_FORCEDETH_NAPI
spin_lock(&np->lock);
napi_schedule(&np->napi); napi_schedule(&np->napi);
/* Disable furthur irq's /* Disable furthur irq's
(msix not enabled with napi) */ (msix not enabled with napi) */
writel(0, base + NvRegIrqMask); writel(0, base + NvRegIrqMask);
spin_unlock(&np->lock);
#else #else
do do
{ {
@@ -3568,10 +3565,10 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data)
if (!(np->msi_flags & NV_MSI_X_ENABLED)) { if (!(np->msi_flags & NV_MSI_X_ENABLED)) {
np->events = readl(base + NvRegIrqStatus); np->events = readl(base + NvRegIrqStatus);
writel(NVREG_IRQSTAT_MASK, base + NvRegIrqStatus); writel(np->events, base + NvRegIrqStatus);
} else { } else {
np->events = readl(base + NvRegMSIXIrqStatus); np->events = readl(base + NvRegMSIXIrqStatus);
writel(NVREG_IRQSTAT_MASK, base + NvRegMSIXIrqStatus); writel(np->events, base + NvRegMSIXIrqStatus);
} }
dprintk(KERN_DEBUG "%s: irq: %08x\n", dev->name, np->events); dprintk(KERN_DEBUG "%s: irq: %08x\n", dev->name, np->events);
if (!(np->events & np->irqmask)) if (!(np->events & np->irqmask))
@@ -3580,15 +3577,12 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data)
nv_msi_workaround(np); nv_msi_workaround(np);
#ifdef CONFIG_FORCEDETH_NAPI #ifdef CONFIG_FORCEDETH_NAPI
spin_lock(&np->lock);
napi_schedule(&np->napi); napi_schedule(&np->napi);
/* Disable furthur irq's /* Disable furthur irq's
(msix not enabled with napi) */ (msix not enabled with napi) */
writel(0, base + NvRegIrqMask); writel(0, base + NvRegIrqMask);
spin_unlock(&np->lock);
#else #else
do do
{ {
@@ -3758,13 +3752,9 @@ static int nv_napi_poll(struct napi_struct *napi, int budget)
if (rx_work < budget) { if (rx_work < budget) {
/* re-enable interrupts /* re-enable interrupts
(msix not enabled in napi) */ (msix not enabled in napi) */
spin_lock_irqsave(&np->lock, flags);
__napi_complete(napi); __napi_complete(napi);
writel(np->irqmask, base + NvRegIrqMask); writel(np->irqmask, base + NvRegIrqMask);
spin_unlock_irqrestore(&np->lock, flags);
} }
return rx_work; return rx_work;
} }