STM32H7: What happened with the CANFD driver?

[Frank-Christian Kruegel <nu...@istda.com>]

Hi!

Some months ago a member of this mailing list submitted a CANFD driver 
for STM32H7. What happened with this driver? Is it stuck in the review 
process? Is additional work to do?

Best regards

Frank-Christian

Re: STM32H7: What happened with the CANFD driver?

[John Rippetoe <jr...@roboticresearch.com>]

Hi guys,

I worked on this driver and opened the PR you both are referring too. I 
have been slammed with other things at work, which have prevented me 
from diving back into this. I will say that I have been actively using 
this driver in it's current state on NuttX 8.2 with no problems. I 
initially published it as a draft because I wanted others to get eyes on 
it and maybe play around with it some more (knowing my time to work on 
it was ending) and poke holes in it's functionality. In reality, it 
could probably be merged without issue since the core functionality is 
there and working.

Most of the issues I mentioned in the PR are related to secondary 
features (RTR, bit rate switching, etc) that have not been tested yet. 
The one thing that should probably be changed before merging this in is 
the issue of a single RCC reset line. In it's current state, resetting 
the peripheral resets both CAN controllers, which really is no good. I 
outlined one possible alternative approach for fixing this in the PR. 
The other thing I was unsure of is whether the dedicated message RAM for 
the device is cacheable:/
/

/"I am uncertain about whether the message RAM is cacheable. The memory 
mapped address falls within the peripheral device space, which as far as 
I can tell is uncacheable. I could be wrong about this, but the driver 
currently seems to work as expected without any cache coherency 
operations in play"/

If anyone has any insight on this, I would appreciate it. At this point, 
I'm fairly certain that space is not cacheable since I haven't run into 
any issues. I'm prepared to be told I am dead wrong though!

I don't currently have the time or means to get this tested on NuttX 
master unfortunately. I /might/ be able to swing a little time here and 
there to help out a little if someone wants to collaborate. I'm sorry to 
have left it in this state! :/

- John


On 7/22/21 12:18 PM, Nathan Hartman wrote:
> On Thu, Jul 22, 2021 at 4:55 AM Frank-Christian Kruegel <nu...@istda.com>
> wrote:
>
>> Hi!
>>
>> Some months ago a member of this mailing list submitted a CANFD driver
>> for STM32H7. What happened with this driver? Is it stuck in the review
>> process? Is additional work to do?
>>
>> Best regards
>>
>> Frank-Christian
>>
> Hello,
>
> Are you referring to PR-2987? [1]
>
> It is still marked as a "Draft" PR and therefore cannot be merged.
>
> I didn't study it in depth but there seems to be a list of unfinished work
> listed there (in the PR description).
>
> Probably the best way to move it forward is to try to contact the PR author
> and perhaps collaborate on finishing any outstanding issues to get this
> ready for review/merge.
>
> [1]
> https://github.com/apache/incubator-nuttx/pull/2987
>
> Cheers
> Nathan
>

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Re: STM32H7: What happened with the CANFD driver?

[Nathan Hartman <ha...@gmail.com>]

On Thu, Jul 22, 2021 at 4:55 AM Frank-Christian Kruegel <nu...@istda.com>
wrote:

> Hi!
>
> Some months ago a member of this mailing list submitted a CANFD driver
> for STM32H7. What happened with this driver? Is it stuck in the review
> process? Is additional work to do?
>
> Best regards
>
> Frank-Christian
>

Hello,

Are you referring to PR-2987? [1]

It is still marked as a "Draft" PR and therefore cannot be merged.

I didn't study it in depth but there seems to be a list of unfinished work
listed there (in the PR description).

Probably the best way to move it forward is to try to contact the PR author
and perhaps collaborate on finishing any outstanding issues to get this
ready for review/merge.

[1]
https://github.com/apache/incubator-nuttx/pull/2987

Cheers
Nathan