Re: [PATCH v3 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace

From: Hao Zhang
Date: Fri May 12 2023 - 03:52:23 EST


Hi Bagas,

On 5/10/2023 12:29 PM, Bagas Sanjaya wrote:
On Sat, Apr 22, 2023 at 03:37:14PM +0800, Hao Zhang wrote:
+Introduction
+---------------------------
+
+Coresight Dummy Trace Module is for the specific devices that kernel
+don't have permission to access or configure, e.g., CoreSight TPDMs
+on Qualcomm platforms. So there need driver to register dummy devices
+as Coresight devices. It may also be used to define components that
+may not have any programming interfaces (e.g, static links), so that
+paths can be established in the driver. Provide Coresight API for
+dummy device operations, such as enabling and disabling dummy devices.
+Build the Coresight path for dummy sink or dummy source for debugging.
+
+Config details
+---------------------------
+
+There are two types of nodes, dummy sink and dummy source. The nodes
+should be observed at the below coresight path::
+
+ ``/sys/bus/coresight/devices``.
+
+e.g.::
+
+ / $ ls -l /sys/bus/coresight/devices | grep dummy
+ dummy0 -> ../../../devices/platform/soc@0/soc@0:dummy_source/dummy0
+ dummy1 -> ../../../devices/platform/soc@0/soc@0:dummy_sink/dummy1

The wording confuses me, so I have to make the improv:

---- >8 ----
diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst
index 7cb59f080c8892..f0a92669288b0c 100644
--- a/Documentation/trace/coresight/coresight-dummy.rst
+++ b/Documentation/trace/coresight/coresight-dummy.rst
@@ -8,27 +8,25 @@ Coresight Dummy Trace Module
:Date: May 2023
Introduction
----------------------------
+------------
-Coresight Dummy Trace Module is for the specific devices that kernel
-don't have permission to access or configure, e.g., CoreSight TPDMs
-on Qualcomm platforms. So there need driver to register dummy devices
-as Coresight devices. It may also be used to define components that
-may not have any programming interfaces (e.g, static links), so that
-paths can be established in the driver. Provide Coresight API for
-dummy device operations, such as enabling and disabling dummy devices.
-Build the Coresight path for dummy sink or dummy source for debugging.
+The Coresight dummy trace module is for the specific devices that kernel don't
+have permission to access or configure, e.g., CoreSight TPDMs on Qualcomm
+platforms. For these devices, a dummy driver is needed to register them as
+Coresight devices. The module may also be used to define components that may
+not have any programming interfaces (e.g, static links), so that paths can be
+created in the driver. It provides Coresight API for operations on dummy
+devices, such as enabling and disabling them. It also provides the Coresight
+dummy sink/source paths for debugging.
Config details
----------------------------
+--------------
-There are two types of nodes, dummy sink and dummy source. The nodes
-should be observed at the below coresight path::
+There are two types of nodes, dummy sink and dummy source. These nodes
+are available at ``/sys/bus/coresight/devices``.
- ``/sys/bus/coresight/devices``.
+Example output::
-e.g.::
-
- / $ ls -l /sys/bus/coresight/devices | grep dummy
+ $ ls -l /sys/bus/coresight/devices | grep dummy
dummy_sink0 -> ../../../devices/platform/soc@0/soc@0:sink/dummy_sink0
dummy_source0 -> ../../../devices/platform/soc@0/soc@0:source/dummy_source0

Thanks.


Thanks for your review and comments, will update it in the next patch series.

Thanks,
Hao