Re: [PATCH] dmaengine: apple-admac: Keep upper bits of REG_BUS_WIDTH

From: Martin Povišer
Date: Sun Oct 29 2023 - 13:10:59 EST



> On 29. 10. 2023, at 18:00, Martin Povišer <povik+lin@xxxxxxxxxxx> wrote:
>
> From: Hector Martin <marcan@xxxxxxxxx>
>
> For RX channels, REG_BUS_WIDTH seems to default to a value of 0xf00, and
> macOS preserves the upper bits when setting the configuration in the
> lower ones. If we reset the upper bits to 0, this causes framing errors
> on suspend/resume (the data stream "tears" and channels get swapped
> around). Keeping the upper bits untouched, like the macOS driver does,
> fixes this issue.
>
> Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
> Reviewed-by: Martin Povišer <povik@xxxxxxxxxxx>
> Signed-off-by: Martin Povišer <povik@xxxxxxxxxxx>
> ---

Please take up v2 instead. I slipped in the wrong email address in here,
which I don’t want to subscribe for kernel spam with.

https://lore.kernel.org/dmaengine/20231029170704.82238-1-povik+lin@xxxxxxxxxxx/T/#u

Thanks!

Kind regards,
Martin