Re: [PATCH v2 1/3] sh: dma: Fix dma channel offset calculation

[Geert Uytterhoeven <geert@linux-m68k.org>]

On Sat, May 27, 2023 at 6:45 PM Artur Rojek <contact@artur-rojek.eu> wrote:
> Various SoCs of the SH3, SH4 and SH4A family, which use this driver,
> feature a differing number of DMA channels, which can be distributed
> between up to two DMAC modules. Existing implementation fails to
> correctly accommodate for all those variations, resulting in wrong
> channel offset calculations and leading to kernel panics.
>
> Rewrite dma_base_addr() in order to properly calculate channel offsets
> in a DMAC module. Fix dmaor_read_reg() and dmaor_write_reg(), so that
> the correct DMAC module base is selected for the DMAOR register.
>
> Fixes: 7f47c7189b3e8f19 ("sh: dma: More legacy cpu dma chainsawing.")
> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
> ---
>
> v2: also handle differing numbers of DMAC modules and channels

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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