[PATCH 0/5] Improvements for atsam BSP and sc16is752 UART.

[Christian Mauderer]

Am 13.02.2018 um 00:34 schrieb Chris Johns:
> On 13/02/2018 00:39, Christian Mauderer wrote:
>> These patches add various improvements for the atsam BSP and for the
>> sc16is752 SPI UART controller.
>>
>> Regarding patch 1: Note that I have thought about an auto detection
>> instead of the option. But I had a board where something responded to
>> the oscillator so that I could initialize it despite the fact that no
>> crystall has been connected. So I think an auto detection would be
>> dangerous.
> 
> I agree with this approach.
> 
> Auto-detection is OK in systems with users however in embedded systems it is
> dangerous. I have a rule, any auto-detection requires a system level module that
> audits the part of a system that has auto-detection and raises any unexpected
> differences as errors. Auto-detection can be hard to avoid in some systems, ie
> PC motherboards, PCI etc.
> 
> I remember back in the mid-90s working on an important system with RAM size
> detection where one of two static RAM chips had started to fail and the system
> adjusted assuming this was all the available memory so no one noticed until many
> many months into operation the application was reconfigured and it ran out of
> memory when it should not have. At the start of the project I had been asked to
> add the memory detection to handle different build variants of the hardware. The
> feature was disabled and I have not been a fan of it ever since.
> 
> Chris
> 

Hello Chris,

thanks for the support for this approach. I mostly wanted to give a
reason why I thought it would be necessary to add another option to the BSP.

Any other remarks regarding the patches? Can I apply them?

Kind regards

Christian

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