Re: [Regression] "iommu/amd: Relax locking in dma_ops path" makes tg3 ethernet transmit queue timeout

From: Kai-Heng Feng
Date: Fri Aug 21 2020 - 09:50:47 EST


Hi Joerg,

> On Aug 21, 2020, at 21:43, Joerg Roedel <jroedel@xxxxxxx> wrote:
>
> Hi Kai,
>
> On Mon, Jun 29, 2020 at 08:33:22PM +0800, Kai-Heng Feng wrote:
>> I am still seeing the issue on v5.8-rc3. The issue goes away as soon
>> as "iommu=off" is added.
>
> Can you probably help with debugging this issue? I've had no luck so far
> getting my hands on a machine with tg3 hardware and an AMD IOMMU.

Of course, I still have the system at my side.

The offending commit is 92d420ec028d ("iommu/amd: Relax locking in dma_ops path"), however be62dbf554c5 ("iommu/amd: Convert AMD iommu driver to the dma-iommu api") removed .map_page entirely so I don't know where to start.

Kai-Heng

>
> Regards,
>
> Joerg