From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH net-next] tg3: inconsistent interrupt value reported Date: Fri, 31 Oct 2008 12:09:08 -0400 Message-ID: <490B2DA4.30903@garzik.org> References: <20081031155421.GB6181@gospo.rdu.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: mcarlson@broadcom.com, netdev@vger.kernel.org, mchan@broadcom.com, davem@davemloft.net To: Andy Gospodarek Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:56313 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751016AbYJaQJO (ORCPT ); Fri, 31 Oct 2008 12:09:14 -0400 In-Reply-To: <20081031155421.GB6181@gospo.rdu.redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Andy Gospodarek wrote: > 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 > --- > > 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