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* [PATCH 1/1] serial: omap-serial: Add support for kernel debugger
@ 2010-11-20 20:51 Cosmin Cojocar
  2010-11-21 10:56 ` Ionut Nicu
  0 siblings, 1 reply; 3+ messages in thread
From: Cosmin Cojocar @ 2010-11-20 20:51 UTC (permalink / raw)
  To: govindraj.raja
  Cc: manjugk, khilman, ben-linux, tklauser, feng.tang, gregkh, alan,
	linux-omap, Cosmin Cojocar

The kgdb invokes the poll_put_char and poll_get_char when communicating
with the host. This patch also changes the initialization order because the
kgdb will check at the very beginning, if there is a valid serial
driver.

Signed-off-by: Cosmin Cojocar <cosmin.cojocar@gmail.com>
---
 drivers/serial/Makefile      |    2 +-
 drivers/serial/omap-serial.c |   38 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index c570576..ad86113 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
+obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
@@ -88,4 +89,3 @@ obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
 obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
 obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
-obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
diff --git a/drivers/serial/omap-serial.c b/drivers/serial/omap-serial.c
index 03a96db..df6ba03 100644
--- a/drivers/serial/omap-serial.c
+++ b/drivers/serial/omap-serial.c
@@ -866,14 +866,44 @@ serial_omap_type(struct uart_port *port)
 	return up->name;
 }
 
+#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
+
+#ifdef CONFIG_CONSOLE_POLL
+static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned int status;
+
+	do {
+		status = serial_in(up, UART_LSR);
+		udelay(1);
+	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
+
+	serial_out(up, UART_TX, ch);
+}
+
+static int serial_omap_poll_get_char(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned int status;
+	int ch;
+
+	do {
+		status = serial_in(up, UART_LSR);
+		udelay(1);
+	} while ((status & UART_LSR_DR) != UART_LSR_DR);
+
+	ch = (int)serial_in(up, UART_RX);
+	return ch;
+}
+#endif
+
 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
 
 static struct uart_omap_port *serial_omap_console_ports[4];
 
 static struct uart_driver serial_omap_reg;
 
-#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
-
 static inline void wait_for_xmitr(struct uart_omap_port *up)
 {
 	unsigned int status, tmout = 10000;
@@ -1022,6 +1052,10 @@ static struct uart_ops serial_omap_pops = {
 	.request_port	= serial_omap_request_port,
 	.config_port	= serial_omap_config_port,
 	.verify_port	= serial_omap_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_put_char  = serial_omap_poll_put_char,
+	.poll_get_char  = serial_omap_poll_get_char,
+#endif
 };
 
 static struct uart_driver serial_omap_reg = {
-- 
1.6.3.3


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH 1/1] serial: omap-serial: Add support for kernel debugger
  2010-11-20 20:51 [PATCH 1/1] serial: omap-serial: Add support for kernel debugger Cosmin Cojocar
@ 2010-11-21 10:56 ` Ionut Nicu
  2010-11-21 13:12   ` Cosmin Cojocar
  0 siblings, 1 reply; 3+ messages in thread
From: Ionut Nicu @ 2010-11-21 10:56 UTC (permalink / raw)
  To: Cosmin Cojocar
  Cc: govindraj.raja, manjugk, khilman, ben-linux, tklauser, feng.tang,
	gregkh, alan, linux-omap

Hi Cosmin,

On Sat, 2010-11-20 at 21:51 +0100, Cosmin Cojocar wrote:
> The kgdb invokes the poll_put_char and poll_get_char when communicating
> with the host. This patch also changes the initialization order because the
> kgdb will check at the very beginning, if there is a valid serial
> driver.
> 
> Signed-off-by: Cosmin Cojocar <cosmin.cojocar@gmail.com>
> ---
>  drivers/serial/Makefile      |    2 +-
>  drivers/serial/omap-serial.c |   38 ++++++++++++++++++++++++++++++++++++--
>  2 files changed, 37 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index c570576..ad86113 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -80,6 +80,7 @@ obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
>  obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
>  obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
>  obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
> +obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
>  obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
>  obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
>  obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
> @@ -88,4 +89,3 @@ obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
>  obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
>  obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
>  obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
> -obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
> diff --git a/drivers/serial/omap-serial.c b/drivers/serial/omap-serial.c
> index 03a96db..df6ba03 100644
> --- a/drivers/serial/omap-serial.c
> +++ b/drivers/serial/omap-serial.c
> @@ -866,14 +866,44 @@ serial_omap_type(struct uart_port *port)
>  	return up->name;
>  }
>  
> +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
> +
> +#ifdef CONFIG_CONSOLE_POLL
> +static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned int status;
> +
> +	do {
> +		status = serial_in(up, UART_LSR);
> +		udelay(1);
> +	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
> +

Shouldn't you use wait_for_xmitr() instead? If you do that, then you
don't need to move the BOTH_EMPTY macro anymore.

> +	serial_out(up, UART_TX, ch);
> +}
> +
> +static int serial_omap_poll_get_char(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned int status;
> +	int ch;
> +
> +	do {
> +		status = serial_in(up, UART_LSR);
> +		udelay(1);
> +	} while ((status & UART_LSR_DR) != UART_LSR_DR);
> +

I think you should be returning NO_POLL_CHAR if the condition is false,
instead of busy looping.

> +	ch = (int)serial_in(up, UART_RX);
> +	return ch;
> +}

I don't think you need the extra ch variable. Just return serial_in(up,
UART_RX).

Cheers,
Ionut.


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH 1/1] serial: omap-serial: Add support for kernel debugger
  2010-11-21 10:56 ` Ionut Nicu
@ 2010-11-21 13:12   ` Cosmin Cojocar
  0 siblings, 0 replies; 3+ messages in thread
From: Cosmin Cojocar @ 2010-11-21 13:12 UTC (permalink / raw)
  To: Ionut Nicu
  Cc: govindraj.raja, manjugk, khilman, ben-linux, tklauser, feng.tang,
	gregkh, alan, linux-omap

Hi Ionut,

Ionut Nicu wrote:
> Hi Cosmin,
> 
> On Sat, 2010-11-20 at 21:51 +0100, Cosmin Cojocar wrote:
>> The kgdb invokes the poll_put_char and poll_get_char when communicating
>> with the host. This patch also changes the initialization order because the
>> kgdb will check at the very beginning, if there is a valid serial
>> driver.
>>
>> Signed-off-by: Cosmin Cojocar <cosmin.cojocar@gmail.com>
>> ---
>>  drivers/serial/Makefile      |    2 +-
>>  drivers/serial/omap-serial.c |   38 ++++++++++++++++++++++++++++++++++++--
>>  2 files changed, 37 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
>> index c570576..ad86113 100644
>> --- a/drivers/serial/Makefile
>> +++ b/drivers/serial/Makefile
>> @@ -80,6 +80,7 @@ obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
>>  obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
>>  obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
>>  obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
>> +obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
>>  obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
>>  obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
>>  obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
>> @@ -88,4 +89,3 @@ obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
>>  obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
>>  obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
>>  obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
>> -obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
>> diff --git a/drivers/serial/omap-serial.c b/drivers/serial/omap-serial.c
>> index 03a96db..df6ba03 100644
>> --- a/drivers/serial/omap-serial.c
>> +++ b/drivers/serial/omap-serial.c
>> @@ -866,14 +866,44 @@ serial_omap_type(struct uart_port *port)
>>  	return up->name;
>>  }
>>  
>> +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
>> +
>> +#ifdef CONFIG_CONSOLE_POLL
>> +static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
>> +{
>> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
>> +	unsigned int status;
>> +
>> +	do {
>> +		status = serial_in(up, UART_LSR);
>> +		udelay(1);
>> +	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
>> +
> 
> Shouldn't you use wait_for_xmitr() instead? If you do that, then you
> don't need to move the BOTH_EMPTY macro anymore.
> 
Initially, I had used the wait_for_xmitr, but the gdb couldn't establish
a connection. I will retest it.

>> +	serial_out(up, UART_TX, ch);
>> +}
>> +
>> +static int serial_omap_poll_get_char(struct uart_port *port)
>> +{
>> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
>> +	unsigned int status;
>> +	int ch;
>> +
>> +	do {
>> +		status = serial_in(up, UART_LSR);
>> +		udelay(1);
>> +	} while ((status & UART_LSR_DR) != UART_LSR_DR);
>> +
> 
> I think you should be returning NO_POLL_CHAR if the condition is false,
> instead of busy looping.
> 
>> +	ch = (int)serial_in(up, UART_RX);
>> +	return ch;
>> +}
> 
> I don't think you need the extra ch variable. Just return serial_in(up,
> UART_RX).
> 
Here, I agree with your comments.

> Cheers,
> Ionut.
> 
> 

Regards,
Cosmin

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-11-21 13:13 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-11-20 20:51 [PATCH 1/1] serial: omap-serial: Add support for kernel debugger Cosmin Cojocar
2010-11-21 10:56 ` Ionut Nicu
2010-11-21 13:12   ` Cosmin Cojocar

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