Re: [PATCH] Revert "arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()"

Catalin Marinas
2022-12-01T17:47:57Z

On Thu, Dec 01, 2022 at 10:29:39AM +0100, Thorsten Leemhuis wrote:
> Has any progress been made to fix this regression? It afaics is not a
> release critical issue, but well, it still would be nice to get this
> fixed before 6.1 is released.

The only (nearly) risk-free "fix" for 6.1 would be to revert the commit
that exposed the driver bug. It doesn't fix the actual bug, it only
makes it less likely to happen.

I like the original commit removing the cache invalidation as it shows
drivers not behaving properly but, as a workaround, we could add a
command line option to force back the old behaviour (defaulting to the
new one) until the driver is fixed.

--
Catalin