[U-Boot] [PATCHv5 3/4] ARM: tegra124: Add an option to disable CoreSight

[Stephen Warren]

On 09/06/2016 12:06 PM, Julian Scheel wrote:
> On 06.09.16 18:54, Stephen Warren wrote:
>> On 09/05/2016 07:29 AM, Julian Scheel wrote:
>>> From: Alban Bedel <alban.bedel at avionic-design.de>
>>>
>>> When running on a SoC with a secure bootloader CoreSight isn't
>>> allowed, so add an option to disable the CoreSight init.
>>
>>> diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
>>
>>> +config ENABLE_CORESIGHT
>>> +    bool "Enable CoreSight"
>>> +    default y
>>
>> Why "default y"? This changes behaviour on all our open development
>> boards. "default y" should be dropped, and the option should be added to
>> the defconfig for your board, or selected by the board's Kconfig option.
>
> It's default yes, because the current codepath has it enabled. This
> patch actually makes it possible to disable CoreSight by setting this
> option to "n". Previously the code in clock_enable_coresight was run
> unconditionally.

Oh right, I read the config option backwards. It's fine as-is then.

>>> diff --git a/arch/arm/mach-tegra/cpu.c b/arch/arm/mach-tegra/cpu.c
>>
>>>  void clock_enable_coresight(int enable)
>>>  {
>>> +#if defined(CONFIG_ENABLE_CORESIGHT)
>>>      u32 rst, src = 2;
>>>
>>>      debug("%s entry\n", __func__);
>>> @@ -402,6 +403,7 @@ void clock_enable_coresight(int enable)
>>>              writel(rst, CSITE_CPU_DBG3_LAR);
>>>          }
>>>      }
>>> +#endif
>>>  }
>>
>> It might be better to ifdef out the call-site. Otherwise, someone
>> reading that code won't have any idea that the function actually does
>> nothing.
>
> Ok, I can change that.