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From: Stephen Hemminger <shemminger@vyatta.com>
To: Michal Schmidt <mschmidt@redhat.com>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] skge: request IRQ on activating the interface
Date: Tue, 22 Sep 2009 09:28:26 -0700	[thread overview]
Message-ID: <20090922092826.5302225c@s6510> (raw)
In-Reply-To: <20090922120127.14242.71353.stgit@localhost.localdomain>

On Tue, 22 Sep 2009 14:01:31 +0200
Michal Schmidt <mschmidt@redhat.com> wrote:

> skge requests IRQ in its probe function. This causes a problem in
> the following real-life scenario with two different NICs in the machine:
> 
> 1. modprobe skge
>    The card is detected as eth0 and requests IRQ 17. Directory
>    /proc/irq/17/eth0 is created.
> 2. There is an udev rule which says this interface should be called
>    eth1, so udev renames eth0 -> eth1.
> 3. modprobe 8139too
>    The Realtek card is detected as eth0. It will be using IRQ 17 too.
> 4. ip link set eth0 up
>    Now 8139too requests IRQ 17.
> 
> The result is:
> WARNING: at fs/proc/generic.c:590 proc_register ...
> proc_dir_entry '17/eth0' already registered
> ...
> 
> And "ls /proc/irq/17" shows two subdirectories, both called eth0.
> 
> Fix it by requesting the IRQ in skge when the interface is activated.
> This works, because interfaces can be renamed only while they are down.
> 
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

No. because two port cards have a single IRQ for both ports.
The choice of ethX in irq name was done because irqbalance looks for this.
Probably better to change skge/sky2 and other devices with same issue
to use skge-N ... for request_irq, and teach irqbalance how to do deal
with it.

  reply	other threads:[~2009-09-22 16:28 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-22 12:01 [PATCH] skge: request IRQ on activating the interface Michal Schmidt
2009-09-22 16:28 ` Stephen Hemminger [this message]
2009-10-01 10:27   ` [PATCH] skge: use unique IRQ name Michal Schmidt
2009-10-01 16:06     ` Stephen Hemminger
2009-10-01 16:50     ` Stephen Hemminger
2009-10-01 18:02       ` Michal Schmidt
2009-10-01 18:13         ` [PATCH v3] " Stephen Hemminger
2009-10-01 20:31           ` David Miller
2009-10-01 22:17             ` David Miller
2009-10-01 17:11     ` [PATCH] sky2: irqname based on pci address Stephen Hemminger
2009-10-01 17:14       ` Stephen Hemminger
2009-10-01 18:03       ` Michal Schmidt
2009-10-01 22:17         ` David Miller

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