Re: [PATCH 03/31] Add debugger entry points for AVR32

From: Jeffrey Merkey
Date: Thu Jan 28 2016 - 15:20:43 EST


On 1/28/16, Hans-Christian Noren Egtvedt <egtvedt@xxxxxxxxxxxx> wrote:
> Around Thu 28 Jan 2016 12:46:17 -0700 or thereabout, Jeffrey Merkey wrote:
>> This patch series adds an export which can be set by system debuggers to
>> direct the hard lockup and soft lockup detector to trigger a breakpoint
>> exception and enter a debugger if one is active. It is assumed that if
>> someone sets this variable, then an breakpoint handler of some sort will
>> be actively loaded or registered via the notify die handler chain.
>>
>> This addition is extremely useful for debugging hard and soft lockups
>> real time and quickly from a console debugger.
>>
>> Signed-off-by: Jeffrey Merkey <jeffmerkey@xxxxxxxxx>
>
> Acked-by: Hans-Christian Egtvedt <egtvedt@xxxxxxxxxxxx>
>
>> ---
>> arch/avr32/include/asm/kdebug.h | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/avr32/include/asm/kdebug.h
>> b/arch/avr32/include/asm/kdebug.h
>> index f930ce2..f67caf0 100644
>> --- a/arch/avr32/include/asm/kdebug.h
>> +++ b/arch/avr32/include/asm/kdebug.h
>> @@ -1,6 +1,10 @@
>> #ifndef __ASM_AVR32_KDEBUG_H
>> #define __ASM_AVR32_KDEBUG_H
>>
>> +static inline void arch_breakpoint(void)
>> +{
>> +}
>
> Will not this just be optimized away? Are you expecting other developers to
> add a no-op assembler instruction into this function body?
>
> <snipp>
> --
> Best regards, Hans-Christian Egtvedt
>

Yes, I am hoping the maintainers of each arch to make a decision about
how they wish to implement this and/or change it. Totally up to you
guys. I need it stubbed in all the arches so it passes test robot
builds for watchdog.c.

Jeff