On Wed, 6 Nov 2019 09:20:39 +0100, Jiri Pirko wrote:

Tue, Nov 05, 2019 at 10:48:58PM CET, jakub.kicinski@netronome.com wrote:

quoted

On Tue, 5 Nov 2019 22:48:26 +0200, Ido Schimmel wrote:  

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On Tue, Nov 05, 2019 at 09:54:48AM -0800, Jakub Kicinski wrote:  

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Hm, the firmware has no log that it keeps? Surely FW runs a lot of
periodic jobs etc which may encounter some error conditions, how do 
you deal with those?    

There are intrusive out-of-tree modules that can get this information.
It's currently not possible to retrieve this information from the
driver. We try to move away from such methods, but it can't happen
overnight. This set and the work done in the firmware team to add this
new TLV is one step towards that goal.
  

quoted

Bottom line is I don't like when data from FW is just blindly passed
to user space.    

The same information will be passed to user space regardless if you use
ethtool / devlink / printk.  

Sure, but the additional hoop to jump through makes it clear that this
is discouraged and it keeps clear separation between the Linux
interfaces and proprietary custom FW.. "stuff".  

Hmm, let me try to understand. So you basically have problem with
passing random FW generated data and putting it to user (via dmesg,
extack). However, ethtool dump is fine. Devlink health reporter is also
fine.

Yup.

That is completely sufficient for async events/errors.
However in this case, we have MSG sent to fw which generates an ERROR
and this error is sent from FW back, as a reaction to this particular
message.

Well, outputting to dmesg is not more synchronous than putting it in
some other device specific facility.

What do you suggest we should use in order to maintain the MSG-ERROR
pairing? Perhaps a separate devlink health reporter just for this?

Again, to be clear - that's future work, right? Kernel logs as
implemented here do not maintain MSG-ERROR pairing.

What do you think?

In all honesty it's hard to tell for sure, because we don't see the FW
and what it needs. That's kind of the point, it's a black box.

I prefer the driver to mediate all the information in a meaningful way.
If you want to report an error regarding a parameter the FW could
communicate some identification of the field and the reason and the
driver can control the output, for example format a string to print to
logs?