Re: [PATCH v3 5/6] serial: imx: update the stop rx,tx procedures

[Uwe Kleine-König]

On Thu, Sep 21, 2017 at 05:18:16PM +0100, Martyn Welch wrote:
> From: Nandor Han 
> 
> According to "Documentation/serial/driver" both procedures should stop
> receiving or sending data. Based on this the procedures should stop the
> activity regardless if DMA is enabled or not.
> 
> This commit updates both imx_stop_{rx|tx} procedures to stop the
> activity and disable the interrupts related to that.
> 
> Signed-off-by: Nandor Han 
> Signed-off-by: Romain Perier 
> Signed-off-by: Martyn Welch 
> ---
>  drivers/tty/serial/imx.c | 36 +---
>  1 file changed, 17 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index ed02783..256b128 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -388,15 +388,14 @@ static void imx_stop_tx(struct uart_port *port)
>   struct imx_port *sport = (struct imx_port *)port;
>   unsigned long temp;
>  
> - /*
> -  * We are maybe in the SMP context, so if the DMA TX thread is running
> -  * on other cpu, we have to wait for it to finish.
> -  */

did you understand this comment you're removing here? I admit I don't
but unless it is non-sensical you're doing something wrong.

Best regards
Uwe

-- 
Pengutronix e.K.   | Uwe Kleine-König|
Industrial Linux Solutions | http://www.pengutronix.de/  |

Re: [PATCH v3 5/6] serial: imx: update the stop rx,tx procedures

[Uwe Kleine-König]

On Thu, Sep 21, 2017 at 05:18:16PM +0100, Martyn Welch wrote:
> From: Nandor Han 
> 
> According to "Documentation/serial/driver" both procedures should stop
> receiving or sending data. Based on this the procedures should stop the
> activity regardless if DMA is enabled or not.
> 
> This commit updates both imx_stop_{rx|tx} procedures to stop the
> activity and disable the interrupts related to that.
> 
> Signed-off-by: Nandor Han 
> Signed-off-by: Romain Perier 
> Signed-off-by: Martyn Welch 
> ---
>  drivers/tty/serial/imx.c | 36 +---
>  1 file changed, 17 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index ed02783..256b128 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -388,15 +388,14 @@ static void imx_stop_tx(struct uart_port *port)
>   struct imx_port *sport = (struct imx_port *)port;
>   unsigned long temp;
>  
> - /*
> -  * We are maybe in the SMP context, so if the DMA TX thread is running
> -  * on other cpu, we have to wait for it to finish.
> -  */

did you understand this comment you're removing here? I admit I don't
but unless it is non-sensical you're doing something wrong.

Best regards
Uwe

-- 
Pengutronix e.K.   | Uwe Kleine-König|
Industrial Linux Solutions | http://www.pengutronix.de/  |

[PATCH v3 5/6] serial: imx: update the stop rx,tx procedures

[Martyn Welch]

From: Nandor Han 

According to "Documentation/serial/driver" both procedures should stop
receiving or sending data. Based on this the procedures should stop the
activity regardless if DMA is enabled or not.

This commit updates both imx_stop_{rx|tx} procedures to stop the
activity and disable the interrupts related to that.

Signed-off-by: Nandor Han 
Signed-off-by: Romain Perier 
Signed-off-by: Martyn Welch 
---
 drivers/tty/serial/imx.c | 36 +---
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index ed02783..256b128 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -388,15 +388,14 @@ static void imx_stop_tx(struct uart_port *port)
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
 
-   /*
-* We are maybe in the SMP context, so if the DMA TX thread is running
-* on other cpu, we have to wait for it to finish.
-*/
-   if (sport->dma_is_enabled && sport->dma_is_txing)
-   return;
+   sport->tx_bytes = 0;
+
+   if (sport->dma_is_enabled)
+   imx_stop_tx_dma(sport);
 
temp = readl(port->membase + UCR1);
-   writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
+   temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN | UCR1_RTSDEN);
+   writel(temp, port->membase + UCR1);
 
/* in rs485 mode disable transmitter if shifter is empty */
if (port->rs485.flags & SER_RS485_ENABLED &&
@@ -423,21 +422,20 @@ static void imx_stop_rx(struct uart_port *port)
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
 
-   if (sport->dma_is_enabled && sport->dma_is_rxing) {
-   if (sport->port.suspended) {
-   dmaengine_terminate_all(sport->dma_chan_rx);
-   sport->dma_is_rxing = 0;
-   } else {
-   return;
-   }
-   }
+   if (sport->dma_is_enabled)
+   imx_stop_rx_dma(sport);
+
+   temp = readl(sport->port.membase + UCR1);
+   temp &= ~UCR1_RRDYEN;
+   writel(temp, sport->port.membase + UCR1);
 
temp = readl(sport->port.membase + UCR2);
-   writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
+   temp &= ~UCR2_ATEN;
+   writel(temp, sport->port.membase + UCR2);
 
-   /* disable the `Receiver Ready Interrrupt` */
-   temp = readl(sport->port.membase + UCR1);
-   writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
+   temp = readl(sport->port.membase + UCR3);
+   temp &= ~UCR3_AWAKEN;
+   writel(temp, sport->port.membase + UCR3);
 }
 
 /*
-- 
1.8.3.1

[PATCH v3 5/6] serial: imx: update the stop rx,tx procedures

[Martyn Welch]

From: Nandor Han 

According to "Documentation/serial/driver" both procedures should stop
receiving or sending data. Based on this the procedures should stop the
activity regardless if DMA is enabled or not.

This commit updates both imx_stop_{rx|tx} procedures to stop the
activity and disable the interrupts related to that.

Signed-off-by: Nandor Han 
Signed-off-by: Romain Perier 
Signed-off-by: Martyn Welch 
---
 drivers/tty/serial/imx.c | 36 +---
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index ed02783..256b128 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -388,15 +388,14 @@ static void imx_stop_tx(struct uart_port *port)
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
 
-   /*
-* We are maybe in the SMP context, so if the DMA TX thread is running
-* on other cpu, we have to wait for it to finish.
-*/
-   if (sport->dma_is_enabled && sport->dma_is_txing)
-   return;
+   sport->tx_bytes = 0;
+
+   if (sport->dma_is_enabled)
+   imx_stop_tx_dma(sport);
 
temp = readl(port->membase + UCR1);
-   writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
+   temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN | UCR1_RTSDEN);
+   writel(temp, port->membase + UCR1);
 
/* in rs485 mode disable transmitter if shifter is empty */
if (port->rs485.flags & SER_RS485_ENABLED &&
@@ -423,21 +422,20 @@ static void imx_stop_rx(struct uart_port *port)
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
 
-   if (sport->dma_is_enabled && sport->dma_is_rxing) {
-   if (sport->port.suspended) {
-   dmaengine_terminate_all(sport->dma_chan_rx);
-   sport->dma_is_rxing = 0;
-   } else {
-   return;
-   }
-   }
+   if (sport->dma_is_enabled)
+   imx_stop_rx_dma(sport);
+
+   temp = readl(sport->port.membase + UCR1);
+   temp &= ~UCR1_RRDYEN;
+   writel(temp, sport->port.membase + UCR1);
 
temp = readl(sport->port.membase + UCR2);
-   writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
+   temp &= ~UCR2_ATEN;
+   writel(temp, sport->port.membase + UCR2);
 
-   /* disable the `Receiver Ready Interrrupt` */
-   temp = readl(sport->port.membase + UCR1);
-   writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
+   temp = readl(sport->port.membase + UCR3);
+   temp &= ~UCR3_AWAKEN;
+   writel(temp, sport->port.membase + UCR3);
 }
 
 /*
-- 
1.8.3.1