Re: [RFC PATCH] coresight: dynamic-replicator: Fix handling of multiple connections

From: Sai Prakash Ranjan
Date: Thu Apr 23 2020 - 08:22:08 EST


Hi Suzuki,

On 2020-04-07 20:23, Suzuki K Poulose wrote:
On 04/07/2020 02:56 PM, Sai Prakash Ranjan wrote:
Hi Suzuki,

On 2020-04-07 18:38, Suzuki K Poulose wrote:
On 04/07/2020 12:29 PM, Sai Prakash Ranjan wrote:
Hi Suzuki,

Thanks for looking into this issue.

On 2020-04-07 15:54, Suzuki K Poulose wrote:
On 04/07/2020 10:46 AM, Sai Prakash Ranjan wrote:

There seems to be two replicators back to back here. What is connected
to the other output of both of them ? Are there any TPIUs ? What happens
if you choose a sink on the other end of "swao_replicator" (ETB ?)


The other outport of swao replicator is connected to EUD which is a
QCOM specific HW which can be used as a sink like USB.
And the other outport of other replicator(replicator_out) is connected to
TPIU.

After boot, what do the idfilter registers read for both the replicators ?


Added some prints in replicator_probe.

ÂÂreplicator probe ret=-517 devname=6046000.replicator idfilter0=0x0 idfilter1=0x0
ÂÂreplicator probe ret=0 devname=6b06000.replicator idfilter0=0xff idfilter1=0xff
ÂÂreplicator probe ret=0 devname=6046000.replicator idfilter0=0xff idfilter1=0xff

Curious to see how the idfilterX is set to 0:
ÂÂÂÂ if that is never used.
ÂÂÂÂÂÂÂ Or
ÂÂÂÂ if the user doesn't reset it back to 0xff.


For both replicators, the default value seems to be 0x0.

Âreplicator probe in res ret=0 devname=6046000.replicator idfilter0=0x0 idfilter1=0x0
Âreplicator probe ret=-517 devname=6046000.replicator idfilter0=0x0 idfilter1=0x0
Âreplicator probe in res ret=0 devname=6b06000.replicator idfilter0=0x0 idfilter1=0x0
Âreplicator probe ret=0 devname=6b06000.replicator idfilter0=0xff idfilter1=0xff
Âreplicator probe in res ret=0 devname=6046000.replicator idfilter0=0x0 idfilter1=0x0
Âreplicator probe ret=0 devname=6046000.replicator idfilter0=0xff idfilter1=0xff

I am not sure how you have added the debugs, but it looks like the
drivers set 0xff for both the port filters on a successful probe.


About the earlier mentioned points on:

1) Disallow turning the replicator ON, when it is already turned ON
2) Do what your patch does. i.e, disable the other end while one end
is turned on.

Do we need 1) and should we go ahead with this?

Thanks,
Sai

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