Re: [PATCH v2 3/6] serial: imx: remove CTSC and CTS handling

From: Uwe Kleine-König
Date: Wed Jul 05 2017 - 09:39:18 EST


Cc += Clemens Gruber + Fabio Estevam

On Wed, Jul 05, 2017 at 03:07:03PM +0200, Romain Perier wrote:
> From: Nandor Han <nandor.han@xxxxxx>
>
> CTSC and CTS are not related to DMA and might add
> disruption in some cases.
>
> Signed-off-by: Romain Perier <romain.perier@xxxxxxxxxxxxx>

If it was Nandor Han who created this patch, it would be great to get
his sob. If it was you, drop the From: line above.

> ---
> drivers/tty/serial/imx.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 5291b86..dd3ebb4 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -1249,11 +1249,6 @@ static void imx_disable_dma(struct imx_port *sport)
> imx_stop_rx_dma(sport);
> imx_stop_tx_dma(sport);
>
> - /* clear UCR2 */
> - temp = readl(sport->port.membase + UCR2);
> - temp &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
> - writel(temp, sport->port.membase + UCR2);
> -

Before this patch imx_disable_dma resulted in the #CTS pin being high
(inactive).

Does this qualify as a fix? If so, you should sort this patch to the
beginning of the series. Did you do test this patch and its effects
separately?

@Clemens: maybe this patch makes a relevant difference when the port is
operated in rs485 mode. Do you care to test?

> imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
>
> sport->dma_is_enabled = 0;
> --
> 1.8.3.1

Best regards
Uwe

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