Re: [PATCH] net: vmxnet3: avoid accessing the data mapped to streaming DMA

[Jia-Ju Bai]

On 2020/8/4 6:59, David Miller wrote:
> From: Jia-Ju Bai <baijiaju@xxxxxxxxxxxxxxx>
> Date: Sun,  2 Aug 2020 21:11:07 +0800
>
> > In vmxnet3_probe_device(), "adapter" is mapped to streaming DMA:
> >    adapter->adapter_pa = dma_map_single(..., adapter, ...);
> >
> > Then "adapter" is accessed at many places in this function.
> >
> > Theses accesses may cause data inconsistency between CPU cache and
> > hardware.
> >
> > To fix this problem, dma_map_single() is called after these accesses.
> >
> > Signed-off-by: Jia-Ju Bai <baijiaju@xxxxxxxxxxxxxxx>
> 'adapter' is accessed everywhere, in the entire driver, not just here
> in the probe function.

Okay, replacing dma_map_single() with dma_alloc_coherent() may be better.
If you think this solution is okay, I can submit a new patch.


Best wishes,
Jia-Ju Bai