Re: [PATCH v4 4/6] can: flexcan: Consolidate and unify state change handling.

[Andri Yngvason <andri.yngvason@marel.com>]

Quoting Marc Kleine-Budde (2014-12-02 12:49:24)
> On 12/01/2014 08:42 PM, Wolfgang Grandegger wrote:
> [...]
> >> Yes. In any case, the warning interrupt is irrelevant, because we have to poll
> >> the state anyway for the other states. Thus the FLEXCAN_HAS_BROKEN_ERR_STATE
> >> flag is irrelevant.
> > 
> > Well, it improves the situation a little bit. But now I understand your
> > point. Yes the Flexcan core is buggy in this respect.
> 
> Yes, just a bit :) This is probably why they added the m_can core on the
> new imx6 soloX.
>
Interesting! Hopefully they'll make a quadX too. ;)
> 
> >> The question that remains is: Should we enable bus error interrupts for all
> >> flexcan cores or should we ignore the issue and allow the users to work around
> >> it (if they wish) using the berr-reporting flag?
> > 
> > Bus error reporting sometimes really harms and therefore I would leave
> > it as-is. There are also more recent cores and it would be nice to known
> > if they have improved the reporting of state changes further. Anyway,
> > this issue should be addressed by a separate patch series.
> 
> >> There is a middle-ground here: We could enable bus error interrupts when we get
> >> the error-warning interrupt and disable them again when the state has reached
> >> error-active again. In that case we would want to keep the BROKEN_ERR_STATE
> >> flag.
> > 
> > Puh, that's far too sophisticated.
> 
> I agree with Wolfgang. The Bus errors can make a system unresponsive to
> unusable. There is still the bus error limiting patch lurking around,
> which works around this problem.
> 
That's fine by me. It's good enough for me anyway, as is. I might get some
testing done on Saturday. 

--
Andri