DMA issues with the SKGE drivers

DMA issues with the SKGE drivers

[Benoît Dufour]

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In 2024, I reported a bug about the SKGE driver, you can see it here:
https://bugzilla.kernel.org/show_bug.cgi?id=219270

Basically, the problem is that the Marvell 88E8001 on my ASUS A8V 
motherboard can only work with 32bit DMA, and if trying to use 64bit 
DMA, the NIC won't work at all and after some time, the operating system 
will become completely unresponsive (on screen tty will stop refresh, 
keyboard and mouse input will stop working too).

The fix is quite easy:

At the very end of the SKGE driver source code, the ASUS A8V motherboard 
(as well as many other boards like the ASUS A8V Deluxe) should be added 
to the list of 32bit DMA boards:
https://github.com/torvalds/linux/blob/508fed6795411f5ab277fd1edc0d7adca4946f23/drivers/net/ethernet/marvell/skge.c#L4150

In the bug report I posted in 2024, I also posted a test case:
https://bugzilla.kernel.org/attachment.cgi?id=306873&action=diff

but actually I guess a better fix would be to dynamically testing if the 
NIC support only 32bit or 64bit DMA too. If 64bit wouldn't be supported, 
this error (or a similar one) should be reported by the card:
PCI error cmd=0x117 status=0x22b0

Do you think it would be doable?

p.s.:
I know that NIC and those motherboards are very old, but I really wish 
those kinds of bugs should be fixed at some point.

-- 
Benoît Dufour

Unfortunately still a student in Computer Science


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Re: DMA issues with the SKGE drivers

[Andrew Lunn]

On Tue, Apr 14, 2026 at 07:23:17PM -0400, Benoît Dufour wrote:
> In 2024, I reported a bug about the SKGE driver, you can see it here:
> https://bugzilla.kernel.org/show_bug.cgi?id=219270
> 
> Basically, the problem is that the Marvell 88E8001 on my ASUS A8V motherboard
> can only work with 32bit DMA, and if trying to use 64bit DMA, the NIC won't
> work at all and after some time, the operating system will become completely
> unresponsive (on screen tty will stop refresh, keyboard and mouse input will
> stop working too).
> 
> The fix is quite easy:
> 
> At the very end of the SKGE driver source code, the ASUS A8V motherboard (as
> well as many other boards like the ASUS A8V Deluxe) should be added to the list
> of 32bit DMA boards:
> https://github.com/torvalds/linux/blob/508fed6795411f5ab277fd1edc0d7adca4946f23
> /drivers/net/ethernet/marvell/skge.c#L4150

Hi Benoît 

Could you submit a patch adding the needed entry for your board?

	Andrew

Re: DMA issues with the SKGE drivers

[Benoît Dufour]

Yes, I guess I'd be able to, but only after testing it.
I'm currently waiting a new cooler that would support the 110 W TDP of 
my Opteron 180 X2.
The previous cooler I tested were definitely not good enough for cooling 
that CPU.
Just running MemTest86+ for too long made the CPU overheat.
Even the Arctic Cooler Freezer 7 CO wasn't good enough.

Le 14/04/2026 à 20:12, Andrew Lunn a écrit :
> On Tue, Apr 14, 2026 at 07:23:17PM -0400, Benoît Dufour wrote:
>> In 2024, I reported a bug about the SKGE driver, you can see it here:
>> https://bugzilla.kernel.org/show_bug.cgi?id=219270
>>
>> Basically, the problem is that the Marvell 88E8001 on my ASUS A8V motherboard
>> can only work with 32bit DMA, and if trying to use 64bit DMA, the NIC won't
>> work at all and after some time, the operating system will become completely
>> unresponsive (on screen tty will stop refresh, keyboard and mouse input will
>> stop working too).
>>
>> The fix is quite easy:
>>
>> At the very end of the SKGE driver source code, the ASUS A8V motherboard (as
>> well as many other boards like the ASUS A8V Deluxe) should be added to the list
>> of 32bit DMA boards:
>> https://github.com/torvalds/linux/blob/508fed6795411f5ab277fd1edc0d7adca4946f23
>> /drivers/net/ethernet/marvell/skge.c#L4150
> Hi Benoît
>
> Could you submit a patch adding the needed entry for your board?
>
> 	Andrew
>
>
-- 
Benoît Dufour

Unfortunately still a student in Computer Science