Re: [PATCH] tg3: netif_carrier_off runs too early; could still be queued when init fails

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David S. Miller wrote:

From: "Michael Chan" <mchan@broadcom.com>
Date: Tue, 21 Feb 2006 08:44:20 -0800

quoted

On Mon, 2006-02-20 at 14:43 -0500, Jeff Mahoney wrote:

quoted

 This patch moves the netif_carrier_off() call from tg3_init_one()->
 tg3_init_link_config() to tg3_open() as is the convention for most
 other network drivers.

I think moving netif_carrier_off() later is the right thing to do. We
can also move it to the end of tg3_init_one() just before returning 0.

Agreed.

quoted

quoted

 I was getting a panic after a tg3 device failed to initialize due to DMA
 failure. The oops pointed to the link watch queue with spinlock debugging
 enabled. Without spinlock debugging, the Oops didn't occur.

 I suspect that the link event was getting queued but not executed until
 after the DMA test had failed and the device was freed. The link event
 was then operating on freed memory, which could contain anything. With this
 patch applied, the Oops no longer occurs. 

DMA test failed? What NIC device do you have? How did it fail?

I get this too with an old 5700 3COM card on sparc64.  I'll get
you some more detailed info later today, hopefully.

Jeff, please get some details for Michael about your failure
case.  Thanks.

dmesg after modprobe tg3:
tg3.c:v3.49 (Feb 2, 2006)
ACPI: PCI Interrupt 0000:0a:02.0[A] -> GSI 24 (level, low) -> IRQ 201
Uhhuh. NMI received for unknown reason 21 on CPU 0.
Dazed and confused, but trying to continue
Do you have a strange power saving mode enabled?
tg3_test_dma() Write the buffer failed -19
tg3: DMA engine test failed, aborting.

relevant lspci output:
0000:0a:02.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5701
Gigabit Ethernet (rev 15)
        Subsystem: Compaq Computer Corporation NC7770 Gigabit Server
Adapter (PCI-X, 10/100/1000-T)
        Flags: 66Mhz, medium devsel, IRQ 201
        Memory at f7df0000 (64-bit, non-prefetchable) [size=64K]
        Expansion ROM at dc080000 [disabled] [size=64K]
        Capabilities: [40] PCI-X non-bridge device.
        Capabilities: [48] Power Management version 2
        Capabilities: [50] Vital Product Data
        Capabilities: [58] Message Signalled Interrupts: 64bit+
Queue=0/3 Enable-

If you need more details, I can try to dig them up. This is a machine
I've only been using for a few days for some testing and I'm not yet
familiar with all the hardware details.

- -Jeff

- --
Jeff Mahoney
SUSE Labs
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