Re: [PATCH v2] dmaengine: rcar-dmac: don't use DMAC error interrupt

[Geert Uytterhoeven]

Hi Morimoto-san,

Thanks for your patch!

On Wed, Jun 13, 2018 at 10:49 AM Kuninori Morimoto
<kuninori.morimoto.gx@xxxxxxxxxxx> wrote:
> From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
>
> Current rcar-dmac is using DMAC error interrupt which will handle all
> channel's error. But in this design, error handling itself will be
> issue if user want to use virtualization, multi OS, etc.
> This patch removes current DMAC error interrupt handling, and handle it
> on each channel interrupt handler.

Just wondering, what's the usage pattern where this causes a problem?
Do you plan to export part of a SYS-DMAC instance to a guest?
How to maintain host/guest isolation?

> --- a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
> +++ b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
> @@ -38,6 +38,7 @@ Required Properties:
>  - interrupt-names: one entry for the error interrupt, named "error", plus one
>    entry per channel, named "ch%u", where %u is the channel number ranging from
>    zero to the number of channels minus one.
> +  # "error" interrupt will be ignored, so far

Again, DT describes hardware, not software policy.
So please drop all changes to the bindings.

With that fixed:
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
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