Re: [PATCH] x86/dma-mapping: override via_no_dac for new VIA PCI bridges

[Christoph Hellwig]

On Mon, Apr 16, 2018 at 05:26:56PM +0800, David Wang wrote:
> PCI bridges integrated in new VIA chipset/SoC have no DAC issue.
> Enable DAC for the platforms with these chipset/SoC can improve DMA performance about
> 20% when DRAM size > 4GB.
> 

So we get an exception to an exception?  Is there any way to figure
out the PCI IDs actually affected?