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

[Kai-Heng Feng]

> On May 18, 2020, at 21:32, Joerg Roedel <jroedel@xxxxxxx> wrote:
> 
> On Mon, May 18, 2020 at 05:06:45PM +0800, Kai-Heng Feng wrote:
>> Particularly, as soon as the spinlock is removed, the issue can be reproduced.
>> Function domain_flush_complete() doesn't seem to affect the status.
>> 
>> However, the .map_page callback was removed by be62dbf554c5
>> ("iommu/amd: Convert AMD iommu driver to the dma-iommu api"), so
>> there's no easy revert for this issue.
>> 
>> This is still reproducible as of today's mainline kernel, v5.7-rc6.
> 
> Is there any error message from the IOMMU driver?
> 

As of mainline kernel, there's no error message from IOMMU driver.
There are some complains from v4.15-rc1:
https://pastebin.ubuntu.com/p/qn4TXkFxsc/

Kai-Heng