OMAP: Enable Magic SysRq on serial console ttyOx

PATCH Superseded Thomas Weber 6 participants 13 messages Jan 19, 2011 – Jan 22, 2011

Share & tools

Thomas Weber

author

2011-01-19 08:41 UTC #0 lore raw

PATCH v2 1/1 OMAP: Enable Magic SysRq on serial console ttyOx

Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.

This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.

Signed-off-by Thomas Weber <[email protected]>

---
Changes from v1: Changed comment

 drivers/serial/omap-serial.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

drivers/serial/omap-serial.c +4 -0

index 1201eff..907be9b 100644
@@ -20,6 +20,10 @@
  * this driver as required for the omap-platform.
  */
 
+#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/console.h>

Signature · 1 line

1.7.4.rc2

Govindraj

Acked-by Govindraj.R on v2 1/1

2011-01-19 09:31 UTC #1 lore raw

Quoted 8 lines · Thomas Weber

Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Signed-off-by Thomas Weber <[email protected]>

Looks fine to me.

Acked-by Govindraj.R <[email protected]>

Quoted 30 lines

---
Changes from v1: Changed comment
drivers/serial/omap-serial.c | 4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
drivers/serial/omap-serial.c +4 -1
index 1201eff..907be9b 100644
@@ -20,6 +20,10 @@
  * this driver as required for the omap-platform.
  */
 
+#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/console.h>
--
1.7.4.rc2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

G, Manjunath Kondaiah

2011-01-19 13:00 UTC #2 lore raw

Quoted 5 lines · Govindraj

Quoted 4 lines · Thomas Weber
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.

Quoted 8 lines

Quoted 4 lines
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>

I tried to use SysRq key on minicom after applying this patch, it looks like it is not triggering sysrq event.

Am I missing anything?

-Manjunath

Thomas Weber

author

2011-01-19 13:31 UTC #3 lore raw

Am 19.01.2011 14:00, schrieb G, Manjunath Kondaiah:

Quoted 13 lines · Govindraj

Quoted 12 lines · Thomas Weber
Quoted 8 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.

Quoted 8 lines

Quoted 1 line
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it looks like it is not triggering sysrq event.
Am I missing anything?
-Manjunath
--

Hello Manjunath,

Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking

I tested it on Devkit8000 (beagle board clone).

Thomas

Govindraj

2011-01-19 13:59 UTC #4 lore raw

Quoted 20 lines · Thomas Weber

Am 19.01.2011 14:00, schrieb G, Manjunath Kondaiah:
Quoted 19 lines · Govindraj
Quoted 5 lines · Thomas Weber
Quoted 4 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
Quoted 8 lines
Quoted 4 lines
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it looks like it is not triggering sysrq event.
Am I missing anything?

Quoted 9 lines

Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).

re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c

Manju,

can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.

drivers/serial/omap-serial.c +4 -0

index 1201eff..6df623e 100644
@@ -20,6 +20,10 @@
  * this driver as required for the omap-platform.
  */
 
+#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/console.h>

@@ -190,7 +194,6 @@ static inline void receive_chars(struct

uart_omap_port *up, int *status)

                        if (up->port.line == up->port.cons->index) {
                                /* Recover the break flag from console xmit */
                                lsr |= up->lsr_break_flag;
-                               up->lsr_break_flag = 0;
                        }

#endif
if (lsr & UART_LSR_BI)

--
Thanks,
Govindraj.R

Thomas Weber

2011-01-20 06:58 UTC #5 lore raw

Am 19.01.2011 14:58, schrieb Govindraj:

Quoted 69 lines · Thomas Weber

Quoted 20 lines
Am 19.01.2011 14:00, schrieb G, Manjunath Kondaiah:
Quoted 19 lines · Govindraj
Quoted 5 lines · Thomas Weber
Quoted 4 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
Quoted 8 lines
Quoted 4 lines
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it looks like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.
drivers/serial/omap-serial.c +4 -1
index 1201eff..6df623e 100644
@@ -20,6 +20,10 @@
  * this driver as required for the omap-platform.
  */
 
+#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/console.h>
@@ -190,7 +194,6 @@ static inline void receive_chars(struct
 uart_omap_port *up, int *status)
                        if (up->port.line == up->port.cons->index) {
                                /* Recover the break flag from console xmit */
                                lsr |= up->lsr_break_flag;
-                               up->lsr_break_flag = 0;
                        }
 #endif
if (lsr & UART_LSR_BI)

Quoted 4 lines

--
Thanks,
Govindraj.R
--

Hello,

both version works for me.

Thomas

G, Manjunath Kondaiah

Tested-by

2011-01-20 11:48 UTC #6 lore raw

In reply to Govindraj

Quoted 34 lines · Govindraj

Quoted 20 lines · Thomas Weber
Am 19.01.2011 14:00, schrieb G, Manjunath Kondaiah:
Quoted 19 lines · Govindraj
Quoted 5 lines · Thomas Weber
Quoted 4 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
Quoted 8 lines
Quoted 4 lines
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it looks like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c

Quoted 7 lines

Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.

With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.

Tested-by Manjunath G Kondaiah <[email protected]>

-Manjunath

Quoted 31 lines

drivers/serial/omap-serial.c +4 -1

index 1201eff..6df623e 100644
@@ -20,6 +20,10 @@
  * this driver as required for the omap-platform.
  */
 
+#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/console.h>

@@ -190,7 +194,6 @@ static inline void receive_chars(struct
 uart_omap_port *up, int *status)
                        if (up->port.line == up->port.cons->index) {
                                /* Recover the break flag from console xmit */
                                lsr |= up->lsr_break_flag;
-                               up->lsr_break_flag = 0;
                        }
 #endif

if (lsr & UART_LSR_BI)

--
Thanks,
Govindraj.R

Anand Gadiyar

2011-01-20 12:19 UTC #7 lore raw

Quoted 7 lines

Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.

Quoted 6 lines

Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 5 lines
Quoted 1 line
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it

looks

Quoted 25 lines

Quoted 17 lines
Quoted 4 lines
Quoted 4 lines
like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Quoted 7 lines
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.

Quoted 7 lines

With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.
Tested-by Manjunath G Kondaiah <[email protected]>
-Manjunath

Not sure what you guys are trying out, but I am able to use sysrq just fine in minicom (using only Thomas' original patch) - you need to send a break sequence, and the way to do this in minicom is to do Ctrl-A followed by F.

Works for me, without the "resetting lsr_break_flag to 0" part.

@Govind,

What are the issues you see in getting sysrq key break sequence without your change? And how is your change fixing this?

- Anand

Govindraj

2011-01-21 07:24 UTC #8 lore raw

Quoted 52 lines · Anand Gadiyar

Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 5 lines
Quoted 1 line
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it
looks
Quoted 25 lines
Quoted 17 lines
Quoted 4 lines
Quoted 4 lines
like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Quoted 7 lines
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.
Quoted 7 lines
With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.
Tested-by Manjunath G Kondaiah <[email protected]>
-Manjunath
Not sure what you guys are trying out, but I am able to use sysrq just fine in minicom (using only Thomas' original patch) - you need to send a break sequence, and the way to do this in minicom is to do Ctrl-A followed by F.

Quoted 6 lines

Works for me, without the "resetting lsr_break_flag to 0" part.
@Govind,
What are the issues you see in getting sysrq key break sequence without your change? And how is your change fixing this?

Actually I was using teraterm on windows platform.
using keyboard to send a break char [alt + b] sometimes
i observed that first break char was getting lost and subsequent break chars where getting
recognized. However using send break option from terterm menu seems to work most of times.
my change can be dropped.

--
Thanks,
Govindraj.R

G, Manjunath Kondaiah

2011-01-21 07:46 UTC #9 lore raw

Quoted 60 lines · Govindraj

Quoted 52 lines · Anand Gadiyar
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 5 lines
Quoted 1 line
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it
looks
Quoted 25 lines
Quoted 17 lines
Quoted 4 lines
Quoted 4 lines
like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Quoted 7 lines
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.
Quoted 7 lines
With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.
Tested-by Manjunath G Kondaiah <[email protected]>
-Manjunath
Not sure what you guys are trying out, but I am able to use sysrq just fine in minicom (using only Thomas' original patch) - you need to send a break sequence, and the way to do this in minicom is to do Ctrl-A followed by F.
Quoted 6 lines
Works for me, without the "resetting lsr_break_flag to 0" part.
@Govind,
What are the issues you see in getting sysrq key break sequence without your change? And how is your change fixing this?

Quoted 7 lines

Actually I was using teraterm on windows platform.
using keyboard to send a break char [alt + b] sometimes
i observed that first break char was getting lost and subsequent break chars where getting
recognized. However using send break option from terterm menu seems to work most of times.
my change can be dropped.

If it is fixing the issue of losing first break character, what is wrong in having this patch?

Do you see any other issues because of this change?

-Manjunath

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

Govindraj

2011-01-21 09:08 UTC #10 lore raw

Quoted 68 lines · Manjunath Kondaiah

Quoted 60 lines · Govindraj
Quoted 52 lines · Anand Gadiyar
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 5 lines
Quoted 1 line
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it
looks
Quoted 25 lines
Quoted 17 lines
Quoted 4 lines
Quoted 4 lines
like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Quoted 7 lines
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.
Quoted 7 lines
With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.
Tested-by Manjunath G Kondaiah <[email protected]>
-Manjunath
Not sure what you guys are trying out, but I am able to use sysrq just fine in minicom (using only Thomas' original patch) - you need to send a break sequence, and the way to do this in minicom is to do Ctrl-A followed by F.
Quoted 6 lines
Works for me, without the "resetting lsr_break_flag to 0" part.
@Govind,
What are the issues you see in getting sysrq key break sequence without your change? And how is your change fixing this?
Quoted 7 lines
Actually I was using teraterm on windows platform.
using keyboard to send a break char [alt + b] sometimes
i observed that first break char was getting lost and subsequent break chars where getting
recognized. However using send break option from terterm menu seems to work most of times.
my change can be dropped.

Quoted 4 lines

If it is fixing the issue of losing first break character, what is wrong in having this patch?
Do you see any other issues because of this change?

Haven't seen any thing else.
Will leave it to Thomas to incorporate if he is willing to take up the change else will post out this change some time later.

--
Thanks,
Govindraj.R
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

Kevin Hilman

2011-01-22 01:03 UTC #11 lore raw

In reply to G, Manjunath Kondaiah

Quoted 68 lines · Manjunath Kondaiah

Quoted 60 lines · Govindraj
Quoted 52 lines · Anand Gadiyar
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 5 lines
Quoted 1 line
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it
looks
Quoted 25 lines
Quoted 17 lines
Quoted 4 lines
Quoted 4 lines
like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Quoted 7 lines
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.
Quoted 7 lines
With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.
Tested-by Manjunath G Kondaiah <[email protected]>
-Manjunath
Not sure what you guys are trying out, but I am able to use sysrq just fine in minicom (using only Thomas' original patch) - you need to send a break sequence, and the way to do this in minicom is to do Ctrl-A followed by F.
Quoted 6 lines
Works for me, without the "resetting lsr_break_flag to 0" part.
@Govind,
What are the issues you see in getting sysrq key break sequence without your change? And how is your change fixing this?
Quoted 7 lines
Actually I was using teraterm on windows platform.
using keyboard to send a break char [alt + b] sometimes
i observed that first break char was getting lost and subsequent break chars where getting
recognized. However using send break option from terterm menu seems to work most of times.
my change can be dropped.

Quoted 4 lines

If it is fixing the issue of losing first break character, what is wrong in having this patch?
Do you see any other issues because of this change?

Were you loosing the first break character because of PM? i.e., if the OMAP is in retention or off while idle, we will always loose the first character. The first character causes the wakeup, but does not make it to the UART.

Is the first break character lost if sleep_while_idle == 0?

Kevin

Govindraj

2011-01-22 17:13 UTC #12 lore raw

Quoted 73 lines · Kevin Hilman

Quoted 71 lines · Manjunath Kondaiah
Quoted 60 lines · Govindraj
Quoted 52 lines · Anand Gadiyar
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Magic SysRq key is not working for OMAP on new serial console ttyOx because SUPPORT_SYSRQ is not defined for omap-serial.
This patch defines SUPPORT_SYSRQ in omap-serial and enables handling of Magic SysRq character.
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
Quoted 5 lines
Quoted 1 line
Signed-off-by Thomas Weber <[email protected]>
Looks fine to me.
Acked-by Govindraj.R <[email protected]>
I tried to use SysRq key on minicom after applying this patch, it
looks
Quoted 25 lines
Quoted 17 lines
Quoted 4 lines
Quoted 4 lines
like it is not triggering sysrq event.
Am I missing anything?
Quoted 9 lines
Quoted 2 lines
-Manjunath
--
Hello Manjunath,
Do you have CONFIG_MAGIC_SYSRQ enabled?
Magic SysRq key in Kernel Hacking
I tested it on Devkit8000 (beagle board clone).
re-setting lsr_break_flag to 0 in receive chars is causing issues in getting sysrq key break sequence on omap-serial.c
Quoted 7 lines
Manju,
can you try this change on your environment. With below change works for me on 3430SDP/4430SDP. key sequence I checked.
[alt + b + t] => shows trace of tasks running. [alt + b + b] => system reboot.
Quoted 7 lines
With below patch, it works fine on TeraTerm. However, I am not able to perform the same on minicom.
Tested-by Manjunath G Kondaiah <[email protected]>
-Manjunath
Not sure what you guys are trying out, but I am able to use sysrq just fine in minicom (using only Thomas' original patch) - you need to send a break sequence, and the way to do this in minicom is to do Ctrl-A followed by F.
Quoted 6 lines
Works for me, without the "resetting lsr_break_flag to 0" part.
@Govind,
What are the issues you see in getting sysrq key break sequence without your change? And how is your change fixing this?
Quoted 7 lines
Actually I was using teraterm on windows platform.
using keyboard to send a break char [alt + b] sometimes
i observed that first break char was getting lost and subsequent break chars where getting
recognized. However using send break option from terterm menu seems to work most of times.
my change can be dropped.
If it is fixing the issue of losing first break character, what is wrong in having this patch?

Quoted 7 lines

Quoted 1 line
Do you see any other issues because of this change?
Were you loosing the first break character because of PM? i.e., if the OMAP is in retention or off while idle, we will always loose the first character. The first character causes the wakeup, but does not make it to the UART.

No, even without PM i.e., even without setting sleep_while_idle and timeouts for uart I observed on windows-teraterm sometimes first break char was getting lost.

--
Thanks,
Govindraj.R