Re: [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts

From: Eric W. Biederman
Date: Sat Aug 22 2009 - 07:49:09 EST


David Dillow <dave@xxxxxxxxxxxxxx> writes:

>
> Re-looking at the code, I'd guess that some IRQ status line is getting
> stuck high, but I don't see why -- we should acknowledge all outstanding
> interrupts each time through the loop, whether we care about them or
> not.
>
> Could reproduce a problem with the following patch applied, and send the
> full dmesg, please?

Here is what I get.

r8169 screaming irq status 00000085 mask 0000ffff event 0000803f napi 0000001d

Eric

> diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
> index b82780d..46cb05a 100644
> --- a/drivers/net/r8169.c
> +++ b/drivers/net/r8169.c
> @@ -3556,6 +3556,7 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
> void __iomem *ioaddr = tp->mmio_addr;
> int handled = 0;
> int status;
> + int count = 0;
>
> /* loop handling interrupts until we have no new ones or
> * we hit a invalid/hotplug case.
> @@ -3564,6 +3565,15 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
> while (status && status != 0xffff) {
> handled = 1;
>
> + if (count++ > 100) {
> + printk_once("r8169 screaming irq status %08x "
> + "mask %08x event %08x napi %08x\n",
> + status, tp->intr_mask, tp->intr_event,
> + tp->napi_event);
> + break;
> + }
> +
> +
> /* Handle all of the error cases first. These will reset
> * the chip, so just exit the loop.
> */
--
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