On 2020-04-27 19:23, Suzuki K Poulose wrote:
On 04/27/2020 10:45 AM, Mike Leach wrote:
[...]
This is not sufficient. You must prevent another session trying to
enable the other port of the replicator as this could silently fail
the "on-going" session. Not ideal. Fail the attempt to enable a port
if the other port is active. You could track this in software and
fail early.
Suzuki
While I have no issue in principle with not enabling a path to a sink
that is not in use - indeed in some cases attaching to unused sinks
can cause back-pressure that slows throughput (cf TPIU) - I am
concerned that this modification is masking an underlying issue with
the platform in question.
Should we decide to enable the diversion of different IDs to different
sinks or allow different sessions go to different sinks, then this has
potential to fail on the SC7180 SoC - and it will be difficult in
future to associate a problem with this discussion.
Mike,
I think thats a good point.
Sai, please could we narrow down this to the real problem and may be
work around it for the "device" ? Do we know which sink is causing the
back pressure ? We could then push the "work around" to the replicator
it is connected to.
Suzuki
Hi Suzuki, Mike,
To add some more to the information provided earlier,
swao_replicator(6b06000) and etf are
in AOSS (Always-On-SubSystem) group. Also TPIU(connected to
qdss_replicator) and EUD(connected
to swao_replicator) sinks are unused.
Please ignore the id filter values provided earlier.
Here are ID filter values after boot and before enabling replicator. As
per
these idfilter values, we should not try to enable replicator if its
already
enabled (in this case for swao_replicator) right?
localhost ~ # cat
/sys/bus/amba/devices/6b06000.replicator/replicator1/mgmt/idfilter0
0x0
localhost ~ # cat
/sys/bus/amba/devices/6b06000.replicator/replicator1/mgmt/idfilter1
0x0
localhost ~ # cat
/sys/bus/amba/devices/6046000.replicator/replicator0/mgmt/idfilter0
0xff
localhost ~ # cat
/sys/bus/amba/devices/6046000.replicator/replicator0/mgmt/idfilter1
0xff
I think the unused sink EUD(also in AOSS group) probably is causing the
backpressure here.
Thanks,
Sai
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