Subject: Re: [RFC][PATCH] net: arinc429: Add ARINC-429 stack

From: Marc Kleine-Budde <[email-masked]>
Date: Tue, 3 Nov 2015 16:15:00 +0100

On 11/03/2015 04:06 PM, Aleksander Morgado wrote:
>> What about maintainability? Why take care of two almost identical
>> subsystems? With making one stack "simpler" you increase, from my point
>> of view, the costs of maintaining even more. If you fix problems in one
>> stack you have to adopt the other, too.
> 
> If they can share common code, that's fine, that probably can be
> worked around if needed. My main issues are actually with all the
> behavior that CAN supports and doesn't make much sense in ARINC, like
> the complex ID filtering scheme for example (ARINC just requires 256
> bits for a minimum filter),

I think it should be possible to use a simple/different filter mechanism
for ARINC packages.

> or the duplex TX/RX setup for channels
> (channels are either RX or TX, not both), or the local
> echoing/loopback (which wouldn't make much sense for TX-only
> channels).

Local echo/loopback comes in two flavours:
- Other socket receive local generate frames, too.
  This is interesting if you want to merge two ARINC node on single
  device.
- Sending socket receives send frame, too. This is useful if you need
  the feedback that the frame has _really_ been send, not just pushed
  into the networking stack.

> The minimum subset of features required by an ARINC driver
> is actually very small. Trying to "fit" ARINC as a subset of CAN may
> actually be harder than keeping it separate maintainability wise.
> Maybe the issue here is that the original patch is too CAN-like while
> it shouldn't be, don't know.

regards,
Marc

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