[PATCH] net: fs_enet: sync rx dma buffer before reading
Jakub Kicinski
kuba at kernel.org
Tue May 24 06:23:36 AEST 2022
On Sat, 21 May 2022 10:44:30 -0700 Jakub Kicinski wrote:
> > Well, I say the contrary.
> >
> > On the mainline the patch may be applied as is, it won't harm.
> >
> > However, it is gets applied to kernel 4.9 (based on the fixes: tag), it
> > will break the driver for at least powerpc 8xx.
>
> I see, we should make a note of that in the commit message so it doesn't
> get sucked into stable.
>
> > I don't know how SWIOTLB works or even what it is, does any of the
> > microcontrollers embedding freescale ethernet uses that at all ?
>
> AFAIU SWIOTLB basically forces the use of bounce buffers even if the
> device can reach the entire DRAM. I think some people also use it for
> added security? IDK. I mostly use it to check if I'm using the DMA API
> "right" :)
If what I said makes sense please repost the patch, the current version
has been dropped from patchwork already.
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