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Date:   Mon, 18 May 2020 15:32:09 +0200
From:   Joerg Roedel <jroedel@suse.de>
To:     Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc:     iommu@lists.linux-foundation.org,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [Regression] "iommu/amd: Relax locking in dma_ops path" makes
 tg3 ethernet transmit queue timeout
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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?