Re: [PATCH v2] serial: sh-sci: disable DMA for uart_console

From: Geert Uytterhoeven
Date: Tue May 14 2019 - 04:30:26 EST


Hi George,

On Mon, May 13, 2019 at 5:48 PM George G. Davis <george_davis@xxxxxxxxxx> wrote:
> As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for
> console UART"), UART console lines use low-level PIO only access functions
> which will conflict with use of the line when DMA is enabled, e.g. when
> the console line is also used for systemd messages. So disable DMA
> support for UART console lines.
>
> Fixes: https://patchwork.kernel.org/patch/10929511/

I don't think this is an appropriate reference, as it points to a patch that
was never applied.

As the problem has basically existed forever, IMHO no Fixes tag
is needed.

> Reported-by: Michael Rodin <mrodin@xxxxxxxxxxxxxx>
> Tested-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx>
> Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
> ---
> v2: Clarify comment regarding DMA support on kernel console,
> add {Tested,Reviewed}-by:, and Cc: linux-stable lines.

Thanks for the update!

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

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.
-- Linus Torvalds