Re: [PATCH v2 2/4] serial: sh-sci: Stop transfers in sci_shutdown()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Jun 24, 2016 at 04:59:14PM +0200, Geert Uytterhoeven wrote:
> Make sure the transmitter and receiver are stopped when shutting down
> the port, and related interrupts are disabled.
> 
> Without this:
>   - New input data may be received into the RX FIFO, possibly
>     triggering a new RX DMA completion,
>   - Transfers will still be enabled on a subsequent startup of the UART,
>     before the UART's FIFOs have been reset, causing reading of stale
>     data.
> 
> Inspired by a patch in the BSP by Koji Matsuoka
> <koji.matsuoka.xm@renesas.com>.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v2:
>   - Do not clear clock source bits, since the serial console relies on
>     them, as reported by Shimoda-san.
> 
> v1 was extracted from "[PATCH/RFC v3 0/4] serial: sh-sci: Add DT DMA
> support".  The issues with the serial console seen before on
> r8a7740/armadillo and sh73a0/kzm9g seem to be gone.  Changes after
> resurrection:
>   - Write zero to also disable related interrupts, as suggested by
>     Laurent Pinchart,
>   - Enhanced patch description.
> ---
>  drivers/tty/serial/sh-sci.c | 5 +++++
>  1 file changed, 5 insertions(+)

This patch does not apply to my tree :(