diff mbox

[v3,1/1] tty: serial: imx: allow breaks to be received when using dma

Message ID 20180220182038.4325-1-troy.kisky@boundarydevices.com (mailing list archive)
State New, archived
Headers show

Commit Message

Troy Kisky Feb. 20, 2018, 6:20 p.m. UTC
This allows me to login after sending a break when service
serial-getty@ttymxc0.service is running

The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors
fixes this by allowing the higher layers to see a break.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Tested-by: Martin Hicks <mort@bork.org>

---
v2: rebase only
v3: change commit message as requested by Fabio,
    add tested-by
---
 drivers/tty/serial/imx.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

Comments

Fabio Estevam Feb. 20, 2018, 6:25 p.m. UTC | #1
On Tue, Feb 20, 2018 at 3:20 PM, Troy Kisky
<troy.kisky@boundarydevices.com> wrote:
> This allows me to login after sending a break when service
> serial-getty@ttymxc0.service is running
>
> The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors
> fixes this by allowing the higher layers to see a break.
>
> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
> Tested-by: Martin Hicks <mort@bork.org>

Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Uwe Kleine-König Feb. 20, 2018, 7:59 p.m. UTC | #2
On Tue, Feb 20, 2018 at 10:20:37AM -0800, Troy Kisky wrote:
> This allows me to login after sending a break when service
> serial-getty@ttymxc0.service is running
> 
> The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors
> fixes this by allowing the higher layers to see a break.
> 
> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
> Tested-by: Martin Hicks <mort@bork.org>
> 
> ---
> v2: rebase only
> v3: change commit message as requested by Fabio,
>     add tested-by
> ---
>  drivers/tty/serial/imx.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 1d7ca382bc12..2eb8c4a20d68 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -927,7 +927,6 @@ static void dma_rx_callback(void *data)
>  	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
>  
>  	if (status == DMA_ERROR) {
> -		dev_err(sport->port.dev, "DMA transaction error.\n");
>  		clear_rx_errors(sport);
>  		return;
>  	}
> @@ -1028,6 +1027,7 @@ static int start_rx_dma(struct imx_port *sport)
>  
>  static void clear_rx_errors(struct imx_port *sport)
>  {
> +	struct tty_port *port = &sport->port.state->port;
>  	unsigned int status_usr1, status_usr2;
>  
>  	status_usr1 = readl(sport->port.membase + USR1);
> @@ -1036,12 +1036,18 @@ static void clear_rx_errors(struct imx_port *sport)
>  	if (status_usr2 & USR2_BRCD) {
>  		sport->port.icount.brk++;
>  		writel(USR2_BRCD, sport->port.membase + USR2);
> -	} else if (status_usr1 & USR1_FRAMERR) {
> -		sport->port.icount.frame++;
> -		writel(USR1_FRAMERR, sport->port.membase + USR1);
> -	} else if (status_usr1 & USR1_PARITYERR) {
> -		sport->port.icount.parity++;
> -		writel(USR1_PARITYERR, sport->port.membase + USR1);
> +		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
> +			sport->port.icount.buf_overrun++;
> +		tty_flip_buffer_push(port);

I think this needs to call uart_handle_break() as imx_rxint() does. Not sure
how to properly handle SYSRQ in the dma case though.

> +	} else {
> +		dev_err(sport->port.dev, "DMA transaction error.\n");
> +		if (status_usr1 & USR1_FRAMERR) {
> +			sport->port.icount.frame++;
> +			writel(USR1_FRAMERR, sport->port.membase + USR1);
> +		} else if (status_usr1 & USR1_PARITYERR) {
> +			sport->port.icount.parity++;
> +			writel(USR1_PARITYERR, sport->port.membase + USR1);
> +		}
>  	}
>  
>  	if (status_usr2 & USR2_ORE) {
> -- 
> 2.14.1
> 
>
Troy Kisky Feb. 20, 2018, 8:25 p.m. UTC | #3
On 2/20/2018 11:59 AM, Uwe Kleine-König wrote:
> On Tue, Feb 20, 2018 at 10:20:37AM -0800, Troy Kisky wrote:
>> This allows me to login after sending a break when service
>> serial-getty@ttymxc0.service is running
>>
>> The "tty_insert_flip_char(port, 0, TTY_BREAK)" in clear_rx_errors
>> fixes this by allowing the higher layers to see a break.
>>
>> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
>> Tested-by: Martin Hicks <mort@bork.org>
>>
>> ---
>> v2: rebase only
>> v3: change commit message as requested by Fabio,
>>     add tested-by
>> ---
>>  drivers/tty/serial/imx.c | 20 +++++++++++++-------
>>  1 file changed, 13 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
>> index 1d7ca382bc12..2eb8c4a20d68 100644
>> --- a/drivers/tty/serial/imx.c
>> +++ b/drivers/tty/serial/imx.c
>> @@ -927,7 +927,6 @@ static void dma_rx_callback(void *data)
>>  	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
>>  
>>  	if (status == DMA_ERROR) {
>> -		dev_err(sport->port.dev, "DMA transaction error.\n");
>>  		clear_rx_errors(sport);
>>  		return;
>>  	}
>> @@ -1028,6 +1027,7 @@ static int start_rx_dma(struct imx_port *sport)
>>  
>>  static void clear_rx_errors(struct imx_port *sport)
>>  {
>> +	struct tty_port *port = &sport->port.state->port;
>>  	unsigned int status_usr1, status_usr2;
>>  
>>  	status_usr1 = readl(sport->port.membase + USR1);
>> @@ -1036,12 +1036,18 @@ static void clear_rx_errors(struct imx_port *sport)
>>  	if (status_usr2 & USR2_BRCD) {
>>  		sport->port.icount.brk++;
>>  		writel(USR2_BRCD, sport->port.membase + USR2);
>> -	} else if (status_usr1 & USR1_FRAMERR) {
>> -		sport->port.icount.frame++;
>> -		writel(USR1_FRAMERR, sport->port.membase + USR1);
>> -	} else if (status_usr1 & USR1_PARITYERR) {
>> -		sport->port.icount.parity++;
>> -		writel(USR1_PARITYERR, sport->port.membase + USR1);
>> +		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
>> +			sport->port.icount.buf_overrun++;
>> +		tty_flip_buffer_push(port);
> 
> I think this needs to call uart_handle_break() as imx_rxint() does. Not sure
> how to properly handle SYSRQ in the dma case though.
> 


SYSRQ is only for the console port, and console port is never dma. But UPF_SAK may be
an issue. I don't know enough about "Secure Attention Key" to say.


Should I add uart_handle_break anyway ?

>> +	} else {
>> +		dev_err(sport->port.dev, "DMA transaction error.\n");
>> +		if (status_usr1 & USR1_FRAMERR) {
>> +			sport->port.icount.frame++;
>> +			writel(USR1_FRAMERR, sport->port.membase + USR1);
>> +		} else if (status_usr1 & USR1_PARITYERR) {
>> +			sport->port.icount.parity++;
>> +			writel(USR1_PARITYERR, sport->port.membase + USR1);
>> +		}
>>  	}
>>  
>>  	if (status_usr2 & USR2_ORE) {
>> -- 
>> 2.14.1
>>
>>
>
Uwe Kleine-König Feb. 21, 2018, 8:17 a.m. UTC | #4
Hello Troy,

On Tue, Feb 20, 2018 at 12:25:16PM -0800, Troy Kisky wrote:
> >> @@ -1028,6 +1027,7 @@ static int start_rx_dma(struct imx_port *sport)
> >>  
> >>  static void clear_rx_errors(struct imx_port *sport)
> >>  {
> >> +	struct tty_port *port = &sport->port.state->port;
> >>  	unsigned int status_usr1, status_usr2;
> >>  
> >>  	status_usr1 = readl(sport->port.membase + USR1);
> >> @@ -1036,12 +1036,18 @@ static void clear_rx_errors(struct imx_port *sport)
> >>  	if (status_usr2 & USR2_BRCD) {
> >>  		sport->port.icount.brk++;
> >>  		writel(USR2_BRCD, sport->port.membase + USR2);
> >> -	} else if (status_usr1 & USR1_FRAMERR) {
> >> -		sport->port.icount.frame++;
> >> -		writel(USR1_FRAMERR, sport->port.membase + USR1);
> >> -	} else if (status_usr1 & USR1_PARITYERR) {
> >> -		sport->port.icount.parity++;
> >> -		writel(USR1_PARITYERR, sport->port.membase + USR1);
> >> +		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
> >> +			sport->port.icount.buf_overrun++;
> >> +		tty_flip_buffer_push(port);
> > 
> > I think this needs to call uart_handle_break() as imx_rxint() does. Not sure
> > how to properly handle SYSRQ in the dma case though.
> > 
> 
> 
> SYSRQ is only for the console port, and console port is never dma. But UPF_SAK may be
> an issue. I don't know enough about "Secure Attention Key" to say.
> 
> 
> Should I add uart_handle_break anyway ?

You're right about both SYSRQ and SAK. I think uart_handle_break is the
right one for the latter.

Best regards
Uwe
diff mbox

Patch

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 1d7ca382bc12..2eb8c4a20d68 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -927,7 +927,6 @@  static void dma_rx_callback(void *data)
 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
 
 	if (status == DMA_ERROR) {
-		dev_err(sport->port.dev, "DMA transaction error.\n");
 		clear_rx_errors(sport);
 		return;
 	}
@@ -1028,6 +1027,7 @@  static int start_rx_dma(struct imx_port *sport)
 
 static void clear_rx_errors(struct imx_port *sport)
 {
+	struct tty_port *port = &sport->port.state->port;
 	unsigned int status_usr1, status_usr2;
 
 	status_usr1 = readl(sport->port.membase + USR1);
@@ -1036,12 +1036,18 @@  static void clear_rx_errors(struct imx_port *sport)
 	if (status_usr2 & USR2_BRCD) {
 		sport->port.icount.brk++;
 		writel(USR2_BRCD, sport->port.membase + USR2);
-	} else if (status_usr1 & USR1_FRAMERR) {
-		sport->port.icount.frame++;
-		writel(USR1_FRAMERR, sport->port.membase + USR1);
-	} else if (status_usr1 & USR1_PARITYERR) {
-		sport->port.icount.parity++;
-		writel(USR1_PARITYERR, sport->port.membase + USR1);
+		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
+			sport->port.icount.buf_overrun++;
+		tty_flip_buffer_push(port);
+	} else {
+		dev_err(sport->port.dev, "DMA transaction error.\n");
+		if (status_usr1 & USR1_FRAMERR) {
+			sport->port.icount.frame++;
+			writel(USR1_FRAMERR, sport->port.membase + USR1);
+		} else if (status_usr1 & USR1_PARITYERR) {
+			sport->port.icount.parity++;
+			writel(USR1_PARITYERR, sport->port.membase + USR1);
+		}
 	}
 
 	if (status_usr2 & USR2_ORE) {