Re: [PATCH v2] iommu/amd: Disable IOMMU on Stoney Ridge systems

[Christoph Hellwig]

On Fri, Nov 29, 2019 at 10:21:54PM +0800, Kai-Heng Feng wrote:
> Serious screen flickering when Stoney Ridge outputs to a 4K monitor.
> 
> According to Alex Deucher, IOMMU isn't enabled on Windows, so let's do
> the same here to avoid screen flickering on 4K monitor.

Disabling the IOMMU entirely seem pretty severe.  Isn't it enough to
identity map the GPU device?