On 24.10.20 07:25, Vincent MAILHOL wrote:
On 24.10.20 01:47, Oliver Hartkopp wrote:
Btw. do you really see any legacy SocketCAN applications (*together*
with your testing application on the same Linux host) where you don't
have the source code to check whether they properly initialize the
reserved/padding bytes?
Do you?
You still didn't answer this hypothetical question. There must be a
reason behind .. :-D
You can not take responsibility for broken implementations on other ECUs.
We clearly share a difference stance on this subject, I think it is
time to close the debate. I agree to go with your solution.
Ok, together with this answer I also can close the debate :-)
I saw your patch. Changing the name from raw_can to len8_dlc clears
the concerns I had for invalid frames. Thank you.
Great! In fact it cost some time in the night where I woke up from sleep
and think about "the overall goal what we want to archive" ;-)
The right naming lets developers make right assumptions about the
functionality. Therefore it always remains tricky - and discussions like
these. I needed two hours to write an rephrase the patch again and again ...
Also the ctrlmode has now a clear target of Classic CAN (CC) in its
name: CC_LEN8_DLC
Thank you also for depreciating the can_dlc field and introducing the
len field in struct can_frame. It is a smart change.
Thanks. I always had the idea to fix this up after the introduction of
CAN FD which uses a 'len' element too. I discovered myself at that time,
that can_dlc was not the best matching choice - but Kernel APIs are
written in stone for a good reason.
So I've checked what people do, when they need to rename structure
elements in the Kernel API in the uapi section and found this:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=31ba514b2fd0495796
I will now test the patch.
So far it only is an idea for naming 'things' - but I'm happy you like it!
IMO we could continue with enabling a CAN driver to support
CAN_CTRLMODE_CC_LEN8_DLC and see how it works in reality with CAN_RAW
and AF_PACKET - and if we would finally need CAN_RAW_LEN8_DLC or not.
Best,
Oliver
