[PATCH 1/3] arm64: dts: juno: add coresight support

On 13/06/16 15:47, Mathieu Poirier wrote:

On 13 June 2016 at 03:18, Sudeep Holla [off-list ref] wrote:

quoted

On 12/06/16 22:57, Mathieu Poirier wrote:

quoted

On 6 June 2016 at 09:59, Sudeep Holla [off-list ref] wrote:

quoted

Most of the debug-related components on Juno are located in the coreSight
subsystem while others are located in the Cortex-Axx clusters, the SCP
subsystem, and in the main system.

Each core in the two processor clusters contain an Embedded Trace
Macrocell(ETM) which generates real-time trace information that trace
tools can use and an ATB trace output that is sent to a funnel before
going to the CoreSight subsystem.

The trace output signals combine with two trace expansions using another
funnel and fed into the Embedded Trace FIFO(ETF0).

The output trace data stream of the funnel is then replicated before it
is sent to either the:
- Trace Port Interface Unit(TPIU), that sends it out using the trace
port.
- ETR that can write the trace data to memory located in the application
    memory space

Hi Sudeep,

Did you try booting this on juno-r0?  On my side the system won't boot
unless I enable the debug power domain by externally connecting to the
system using DS-5.

As you have already realized that you need SCPI power domain patches for
the functionality. However, in absence of those patches or when it's
disabled, it shouldn't cause any boot or runtime issues. Only ETM or
coresight won't work. If it's causing any crash or hang, please do let
me know, that needs to be fixed. I have only tested with latest
firmware. Let me know the details of hang/crash and firmware version you
are using.

We have a problem then.  Booting with this branch[1] and the 3 DT
patches from this set the system hangs.  But before going any further
I'd bet the FW on my board is too old.  This is what I get on my side:

RM V2M-Juno Boot loader v1.0.0
HBI0262 build 1684

ARM V2M_Juno Firmware v1.3.4
Build Date: Aug 27 2015

Yes looks old *but* these are motherboard firmware, while I was
interested in SCP firmware. Anyways can you provide more details on the
hang (where/what/...)? Also the boot log(what ever you are getting out
if any)

-- 
Regards,
Sudeep