Re: [PATCH] net-tg3: Initialize REG_BASE_ADDR at PCI config offset 120 to 0

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 12/09/2013 10:22 PM, Natarajan Gurumoorthy wrote:

> Michael,
>        We had crashes when the PCI config space got scanned via
> /sys/devices/pcixxxx/....../config.

> I agree that this fix will not help if the scan happens before the tg3
> driver gets loaded.

    Then perhaps a better place for such fixup would be a PCI quirk?

> Regards
> Nat

> On Mon, Dec 9, 2013 at 11:00 AM, Michael Chan <mchan@broadcom.com> wrote:
>> On Mon, 2013-12-09 at 10:43 -0800, Nat Gurumoorthy wrote:
>>> The new tg3 driver leaves REG_BASE_ADDR (PCI config offset 120)
>>> uninitialized. From power on reset this register may have garbage in it. The
>>> Register Base Address register defines the device local address of a
>>> register. The data pointed to by this location is read or written using
>>> the Register Data register (PCI config offset 128). When REG_BASE_ADDR has
>>> garbage any read or write of Register Data Register (PCI 128) will cause the
>>> PCI bus to lock up. The TCO watchdog will fire and bring down the system.


>> Is this to prevent problem from other software that may be scanning the
>> PCI config space?  It won't help if this happens before the tg3 driver
>> is loaded, right?

>> Thanks.

WBR, Sergei