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From: Peter Korsgaard <jacmet@sunsite•dk>
To: Wu Fengguang <wfg@linux•intel.com>, dbrownell@users•sourceforge.net
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH] dm9601: handle corrupt mac address
Date: Tue, 06 Jan 2009 09:42:01 +0100	[thread overview]
Message-ID: <874p0cvnae.fsf@macbook.be.48ers.dk> (raw)
In-Reply-To: <20090106082928.GB19690@localhost> (Wu Fengguang's message of "Tue\, 6 Jan 2009 16\:29\:28 +0800")

>>>>> "Wu" == Wu Fengguang <wfg@linux•intel.com> writes:

Hi,

 >> Do we automatically get a random address in netdev nowadays without
 >> calling random_ether_addr? I didn't know that.

 Wu> I confirmed based on both code review and tests.
 Wu> The logic goes like this in usbnet.c:

 Wu>   80 // randomly generated ethernet address
 Wu>   81 static u8       node_id [ETH_ALEN];
 Wu> ...
 Wu> 1118 int
 Wu> 1119 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
 Wu> 1120 {
 Wu> ...
 Wu> 1168         dev->net = net;
 Wu> 1169         strcpy (net->name, "usb%d");
 Wu> 1170         memcpy (net->dev_addr, node_id, sizeof node_id);
 Wu> ...

So what happens if you plug in 2 devices without an EEPROM? Do they
get the same MAC address? That seems broken.

 >> Anyway, I would prefer to add a dev_warn mentioning the fact that
 >> we're using a random address (and which one).

 Wu> I'll do that in another patch. Since I'd like to add one more similar
 Wu> warning to dm9601_set_mac_address(). That warning helped me identify
 Wu> this bug.

Ok.

-- 
Bye, Peter Korsgaard

  reply	other threads:[~2009-01-06  8:42 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-06  6:14 [PATCH] dm9601: handle corrupt mac address Wu Fengguang
2009-01-06  8:04 ` Peter Korsgaard
2009-01-06  8:29   ` Wu Fengguang
2009-01-06  8:42     ` Peter Korsgaard [this message]
2009-01-06  9:50       ` Wu Fengguang
2009-01-06 10:28       ` David Brownell
2009-01-06 10:56         ` Peter Korsgaard
2009-01-06 18:55   ` David Miller

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