Subject: [PATCH 1/1] Disable CONFIG_UACCESS_WITH_MEMCPY in Atmel config.

From: [email-masked] (Jean-Christian de Rivaz)
Date: Tue, 29 Sep 2015 22:59:46 +0200

Le 29. 09. 15 22:35, Uwe Kleine-K?nig a ?crit :
> Hello,
>
> On Tue, Sep 29, 2015 at 10:03:07PM +0200, jc at eclis.ch wrote:
>> From: Jean-Christian de Rivaz <[email-masked]>
>>
>> According to Russell King:
>> In any case, unless you have a Marvell platform, you should have this
>> disabled - it provides a performance boost for Marvell platforms, but
>> degrades performance everywhere else.  Please ensure that you disable
>> CONFIG_UACCESS_WITH_MEMCPY.
>>
>> Signed-off-by: Jean-Christian de Rivaz <[email-masked]>
>> ---
>>   arch/arm/configs/at91_dt_defconfig |    2 +-
>>   arch/arm/configs/sama5_defconfig   |    2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/configs/at91_dt_defconfig b/arch/arm/configs/at91_dt_defconfig
>> index 090c5b2..1807d7f 100644
>> --- a/arch/arm/configs/at91_dt_defconfig
>> +++ b/arch/arm/configs/at91_dt_defconfig
>> @@ -21,7 +21,7 @@ CONFIG_SOC_SAM_V4_V5=y
>>   CONFIG_SOC_AT91RM9200=y
>>   CONFIG_SOC_AT91SAM9=y
>>   CONFIG_AEABI=y
>> -CONFIG_UACCESS_WITH_MEMCPY=y
>> +# CONFIG_UACCESS_WITH_MEMCPY is not set
>>   CONFIG_ZBOOT_ROM_TEXT=0x0
>>   CONFIG_ZBOOT_ROM_BSS=0x0
>>   CONFIG_ARM_APPENDED_DTB=y
> What is the reason to add the "# ... is not set" line? Given the default
> line of UACCESS_WITH_MEMCPY I suggest to just drop the line without
> replacement in the defconfigs.
>

Hi Uwe,

Without the explicit disabling, the user will be asked and could 
possibly give the wrong answer as the help look as a cool feature and 
the condition is very hard to understand.

Regards,
Jean-Christian