Re: [PATCH net-next] tg3: inconsistent interrupt value reported
From: Jeff Garzik <hidden>
Date: 2008-10-31 16:09:14
Andy Gospodarek wrote:
quoted hunk ↗ jump to hunk
Systems that use MSI do not report the correct 'Interrupt' value in ifconfig output. This patch sets dev->irq after initializing the interrupt as the value will change when using MSI. I suspect this is a problem with a lot of drivers, so I'll snoop around and post some more patches if needed. Signed-off-by: Andy Gospodarek <andy@greyhouse.net> --- tg3.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index eb9f8f3..fa95e99 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c@@ -7892,6 +7892,7 @@ static int tg3_request_irq(struct tg3 *tp) irq_handler_t fn; unsigned long flags; struct net_device *dev = tp->dev; + int ret; if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) { fn = tg3_msi;@@ -7904,7 +7905,9 @@ static int tg3_request_irq(struct tg3 *tp) fn = tg3_interrupt_tagged; flags = IRQF_SHARED | IRQF_SAMPLE_RANDOM; } - return (request_irq(tp->pdev->irq, fn, flags, dev->name, dev)); + ret = request_irq(tp->pdev->irq, fn, flags, dev->name, dev); + dev->irq = tp->pdev->irq; + return ret;
The ifconfig value is useless, and was never designed to carry and display that kind of information (MSI vectors, etc.). In fact, part of the reason why the ethtool bus-id information was added was to give better insight into the hardware attached to the device, notably including the interrupt information. In modern drivers (read: newer than [E]ISA), dev->irq use is inconsistent and largely for __best effort__ display purposes only. I'd argue that a policy of leaving dev->irq at zero might be a better idea. That ensures users do not pay attention to what is already an inconsistent/truncate/device-dependent piece of information. Jeff