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* [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt
@ 2021-04-14  7:18 Rasmus Villemoes
  2021-04-14  7:18 ` [PATCH v4 1/2] timer: mpc83xx_timer: fix build with CONFIG_{HW_, }WATCHDOG Rasmus Villemoes
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Rasmus Villemoes @ 2021-04-14  7:18 UTC (permalink / raw)
  To: u-boot

This is a resend of v3 from a year ago. Please consider applying.

v4: rebase to current master.

v3: add fixup patch for mpc83xx_timer, add documentation hunk to
README, also update m68k instead of only ppc.

v2: add documentation comment

Rasmus Villemoes (2):
  timer: mpc83xx_timer: fix build with CONFIG_{HW_,}WATCHDOG
  allow opting out of WATCHDOG_RESET() from timer interrupt

 README                        | 9 +++++++++
 arch/m68k/lib/time.c          | 2 +-
 arch/powerpc/lib/interrupts.c | 2 +-
 drivers/timer/mpc83xx_timer.c | 6 +++++-
 4 files changed, 16 insertions(+), 3 deletions(-)

-- 
2.29.2

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v4 1/2] timer: mpc83xx_timer: fix build with CONFIG_{HW_, }WATCHDOG
  2021-04-14  7:18 [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
@ 2021-04-14  7:18 ` Rasmus Villemoes
  2021-04-14  7:18 ` [PATCH v4 2/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
  2021-04-26 20:21 ` [PATCH v4 0/2] " Rasmus Villemoes
  2 siblings, 0 replies; 6+ messages in thread
From: Rasmus Villemoes @ 2021-04-14  7:18 UTC (permalink / raw)
  To: u-boot

The code, which is likely copied from arch/powerpc/lib/interrupts.c,
lacks a fallback definition of CONFIG_SYS_WATCHDOG_FREQ and refers to
a non-existing timestamp variable - obviously priv->timestamp is
meant.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
---
 drivers/timer/mpc83xx_timer.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/timer/mpc83xx_timer.c b/drivers/timer/mpc83xx_timer.c
index f4f6e90387..9adb4b4cab 100644
--- a/drivers/timer/mpc83xx_timer.c
+++ b/drivers/timer/mpc83xx_timer.c
@@ -20,6 +20,10 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#ifndef CONFIG_SYS_WATCHDOG_FREQ
+#define CONFIG_SYS_WATCHDOG_FREQ (CONFIG_SYS_HZ / 2)
+#endif
+
 /**
  * struct mpc83xx_timer_priv - Private data structure for MPC83xx timer driver
  * @decrementer_count: Value to which the decrementer register should be re-set
@@ -171,7 +175,7 @@ void timer_interrupt(struct pt_regs *regs)
 	priv->timestamp++;
 
 #if defined(CONFIG_WATCHDOG) || defined(CONFIG_HW_WATCHDOG)
-	if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
+	if ((priv->timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
 		WATCHDOG_RESET();
 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 
-- 
2.29.2

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v4 2/2] allow opting out of WATCHDOG_RESET() from timer interrupt
  2021-04-14  7:18 [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
  2021-04-14  7:18 ` [PATCH v4 1/2] timer: mpc83xx_timer: fix build with CONFIG_{HW_, }WATCHDOG Rasmus Villemoes
@ 2021-04-14  7:18 ` Rasmus Villemoes
  2021-04-26 20:21 ` [PATCH v4 0/2] " Rasmus Villemoes
  2 siblings, 0 replies; 6+ messages in thread
From: Rasmus Villemoes @ 2021-04-14  7:18 UTC (permalink / raw)
  To: u-boot

Having WATCHDOG_RESET() called automatically from the timer interrupt
runs counter to the idea of a watchdog device - if the board runs into
an infinite loops with interrupts still enabled, the watchdog will
never fire.

When using CONFIG_(SPL_)WDT, the watchdog_reset function is a lot more
complicated than just poking a few SOC-specific registers - it
involves accessing all kinds of global data, and if the interrupt
happens at the wrong time (say, in the middle of an WATCHDOG_RESET()
call from ordinary code), that can end up corrupting said global data.

Allow the board to opt out of calling WATCHDOG_RESET() from the timer
interrupt handler by setting CONFIG_SYS_WATCHDOG_FREQ to 0 - as that
setting is currently nonsensical (it would be compile-time
divide-by-zero), it cannot affect any existing boards.

Add documentation for both the existing and extended meaning of
CONFIG_SYS_WATCHDOG_FREQ.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
---
 README                        | 9 +++++++++
 arch/m68k/lib/time.c          | 2 +-
 arch/powerpc/lib/interrupts.c | 2 +-
 drivers/timer/mpc83xx_timer.c | 2 +-
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/README b/README
index a565748e43..ad13092bbb 100644
--- a/README
+++ b/README
@@ -747,6 +747,15 @@ The following options need to be configured:
 		SoC, then define this variable and provide board
 		specific code for the "hw_watchdog_reset" function.
 
+		CONFIG_SYS_WATCHDOG_FREQ
+		Some platforms automatically call WATCHDOG_RESET()
+		from the timer interrupt handler every
+		CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
+		board configuration file, a default of CONFIG_SYS_HZ/2
+		(i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
+		to 0 disables calling WATCHDOG_RESET() from the timer
+		interrupt.
+
 - Real-Time Clock:
 
 		When CONFIG_CMD_DATE is selected, the type of the RTC
diff --git a/arch/m68k/lib/time.c b/arch/m68k/lib/time.c
index cbe29e72a8..ebb2ac54db 100644
--- a/arch/m68k/lib/time.c
+++ b/arch/m68k/lib/time.c
@@ -71,7 +71,7 @@ void dtimer_interrupt(void *not_used)
 		timestamp++;
 
 		#if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
-		if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) {
+		if (CONFIG_SYS_WATCHDOG_FREQ && (timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) {
 			WATCHDOG_RESET ();
 		}
 		#endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
diff --git a/arch/powerpc/lib/interrupts.c b/arch/powerpc/lib/interrupts.c
index 73f270002c..5ba4cd0c13 100644
--- a/arch/powerpc/lib/interrupts.c
+++ b/arch/powerpc/lib/interrupts.c
@@ -80,7 +80,7 @@ void timer_interrupt(struct pt_regs *regs)
 	timestamp++;
 
 #if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
-	if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
+	if (CONFIG_SYS_WATCHDOG_FREQ && (timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
 		WATCHDOG_RESET ();
 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 
diff --git a/drivers/timer/mpc83xx_timer.c b/drivers/timer/mpc83xx_timer.c
index 9adb4b4cab..952293195f 100644
--- a/drivers/timer/mpc83xx_timer.c
+++ b/drivers/timer/mpc83xx_timer.c
@@ -175,7 +175,7 @@ void timer_interrupt(struct pt_regs *regs)
 	priv->timestamp++;
 
 #if defined(CONFIG_WATCHDOG) || defined(CONFIG_HW_WATCHDOG)
-	if ((priv->timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
+	if (CONFIG_SYS_WATCHDOG_FREQ && (priv->timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
 		WATCHDOG_RESET();
 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 
-- 
2.29.2

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt
  2021-04-14  7:18 [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
  2021-04-14  7:18 ` [PATCH v4 1/2] timer: mpc83xx_timer: fix build with CONFIG_{HW_, }WATCHDOG Rasmus Villemoes
  2021-04-14  7:18 ` [PATCH v4 2/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
@ 2021-04-26 20:21 ` Rasmus Villemoes
  2021-04-26 20:47   ` Tom Rini
  2 siblings, 1 reply; 6+ messages in thread
From: Rasmus Villemoes @ 2021-04-26 20:21 UTC (permalink / raw)
  To: u-boot

On 14/04/2021 09.18, Rasmus Villemoes wrote:
> This is a resend of v3 from a year ago. Please consider applying.
> 
> v4: rebase to current master.
> 
> v3: add fixup patch for mpc83xx_timer, add documentation hunk to
> README, also update m68k instead of only ppc.
> 
> v2: add documentation comment
> 
> Rasmus Villemoes (2):
>   timer: mpc83xx_timer: fix build with CONFIG_{HW_,}WATCHDOG
>   allow opting out of WATCHDOG_RESET() from timer interrupt
> 
>  README                        | 9 +++++++++
>  arch/m68k/lib/time.c          | 2 +-
>  arch/powerpc/lib/interrupts.c | 2 +-
>  drivers/timer/mpc83xx_timer.c | 6 +++++-
>  4 files changed, 16 insertions(+), 3 deletions(-)
> 

ping

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt
  2021-04-26 20:21 ` [PATCH v4 0/2] " Rasmus Villemoes
@ 2021-04-26 20:47   ` Tom Rini
  2021-04-27  8:20     ` Stefan Roese
  0 siblings, 1 reply; 6+ messages in thread
From: Tom Rini @ 2021-04-26 20:47 UTC (permalink / raw)
  To: u-boot

On Mon, Apr 26, 2021 at 10:21:30PM +0200, Rasmus Villemoes wrote:
> On 14/04/2021 09.18, Rasmus Villemoes wrote:
> > This is a resend of v3 from a year ago. Please consider applying.
> > 
> > v4: rebase to current master.
> > 
> > v3: add fixup patch for mpc83xx_timer, add documentation hunk to
> > README, also update m68k instead of only ppc.
> > 
> > v2: add documentation comment
> > 
> > Rasmus Villemoes (2):
> >   timer: mpc83xx_timer: fix build with CONFIG_{HW_,}WATCHDOG
> >   allow opting out of WATCHDOG_RESET() from timer interrupt
> > 
> >  README                        | 9 +++++++++
> >  arch/m68k/lib/time.c          | 2 +-
> >  arch/powerpc/lib/interrupts.c | 2 +-
> >  drivers/timer/mpc83xx_timer.c | 6 +++++-
> >  4 files changed, 16 insertions(+), 3 deletions(-)
> > 
> 
> ping

As watchdog stuff, Stefan?


-- 
Tom
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt
  2021-04-26 20:47   ` Tom Rini
@ 2021-04-27  8:20     ` Stefan Roese
  0 siblings, 0 replies; 6+ messages in thread
From: Stefan Roese @ 2021-04-27  8:20 UTC (permalink / raw)
  To: u-boot

On 26.04.21 22:47, Tom Rini wrote:
> On Mon, Apr 26, 2021 at 10:21:30PM +0200, Rasmus Villemoes wrote:
>> On 14/04/2021 09.18, Rasmus Villemoes wrote:
>>> This is a resend of v3 from a year ago. Please consider applying.
>>>
>>> v4: rebase to current master.
>>>
>>> v3: add fixup patch for mpc83xx_timer, add documentation hunk to
>>> README, also update m68k instead of only ppc.
>>>
>>> v2: add documentation comment
>>>
>>> Rasmus Villemoes (2):
>>>    timer: mpc83xx_timer: fix build with CONFIG_{HW_,}WATCHDOG
>>>    allow opting out of WATCHDOG_RESET() from timer interrupt
>>>
>>>   README                        | 9 +++++++++
>>>   arch/m68k/lib/time.c          | 2 +-
>>>   arch/powerpc/lib/interrupts.c | 2 +-
>>>   drivers/timer/mpc83xx_timer.c | 6 +++++-
>>>   4 files changed, 16 insertions(+), 3 deletions(-)
>>>
>>
>> ping
> 
> As watchdog stuff, Stefan?

Looks good. I've pulled all ready WDT related patches and will send
the pull request shortly.

Thanks,
Stefan

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-04-27  8:20 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-14  7:18 [PATCH v4 0/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
2021-04-14  7:18 ` [PATCH v4 1/2] timer: mpc83xx_timer: fix build with CONFIG_{HW_, }WATCHDOG Rasmus Villemoes
2021-04-14  7:18 ` [PATCH v4 2/2] allow opting out of WATCHDOG_RESET() from timer interrupt Rasmus Villemoes
2021-04-26 20:21 ` [PATCH v4 0/2] " Rasmus Villemoes
2021-04-26 20:47   ` Tom Rini
2021-04-27  8:20     ` Stefan Roese

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