Re: [PATCH 15/21] ARM: dma-mapping: always invalidate WT caches before DMA

[Linus Walleij]

On Mon, Mar 27, 2023 at 2:16 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:

> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Most ARM CPUs can have write-back caches and that require
> cache management to be done in the dma_sync_*_for_device()
> operation. This is typically done in both writeback and
> writethrough mode.
>
> The cache-v4.S (arm720/740/7tdmi/9tdmi) and cache-v4wt.S
> (arm920t, arm940t) implementations are the exception here,
> and only do the cache management after the DMA is complete,
> in the dma_sync_*_for_cpu() operation.
>
> Change this for consistency with the other platforms. This
> should have no user visible effect.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Looks good to me.
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij