Re: pch_can: Data transmission stops after dropped packet

[Michael Pellegrini <mikep86@gmail.com>]

Michael Pellegrini <mikep86 <at> gmail.com> writes:

> > I have implemented a better solution now using different sets of
> > registers for tx and rx. This avoids locking in the RX path as well.
> > Furthermore, pch_can now uses spin_[un]lock_bh. Would be nice if you
> > could give the pch_can and c_can_pci driver a try when time permits.
> 
> Great! I'm happy to test these drivers out.  In addition to testing
> these drivers through my application, I'm looking at creating a soak test to
> really push the interface (and the driver) hard.  That test will probably be
> ready early next week.  I will get back to you with the results.

I have some results.  

The good news: The c_can driver appears to work very well.  It has been running
successfully under the soak test for 18 hours and counting.

The bad news: The pch_can driver is exhibiting the transmission problem again.
The soak test causes the driver to fail within minutes.

Details of the soak test:

There are two systems involved in the test: the PCH-System and an External Node.
The External Node transmits data at a high rate, bringing bus utilization to
~35%.
The PCH-System also transmits data, in bursts of 10 messages every 5 ms.
Combined, the two systems utilize ~90% of bus bandwidth.
The PCH-System is constantly checking that it is receiving data from the
External Node at the expected rate and in the expected order.

- Mike