diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/coresight/coresight-dummy.rst | 32 | ||||
| -rw-r--r-- | Documentation/trace/hisi-ptt.rst | 12 |
2 files changed, 41 insertions, 3 deletions
diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst new file mode 100644 index 000000000000..eff7c553ee6c --- /dev/null +++ b/Documentation/trace/coresight/coresight-dummy.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +Coresight Dummy Trace Module +============================= + + :Author: Hao Zhang <quic_hazha@quicinc.com> + :Date: June 2023 + +Introduction +------------ + +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, 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. These nodes +are available at ``/sys/bus/coresight/devices``. + +Example output:: + + $ 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 diff --git a/Documentation/trace/hisi-ptt.rst b/Documentation/trace/hisi-ptt.rst index 4f87d8e21065..989255eb5622 100644 --- a/Documentation/trace/hisi-ptt.rst +++ b/Documentation/trace/hisi-ptt.rst @@ -148,14 +148,20 @@ For example, if the desired filter is Endpoint function 0000:01:00.1 the filter value will be 0x00101. If the desired filter is Root Port 0000:00:10.0 then then filter value is calculated as 0x80001. +The driver also presents every supported Root Port and Requester filter through +sysfs. Each filter will be an individual file with name of its related PCIe +device name (domain:bus:device.function). The files of Root Port filters are +under $(PTT PMU dir)/root_port_filters and files of Requester filters +are under $(PTT PMU dir)/requester_filters. + Note that multiple Root Ports can be specified at one time, but only one Endpoint function can be specified in one trace. Specifying both Root Port and function at the same time is not supported. Driver maintains a list of available filters and will check the invalid inputs. -Currently the available filters are detected in driver's probe. If the supported -devices are removed/added after probe, you may need to reload the driver to update -the filters. +The available filters will be dynamically updated, which means you will always +get correct filter information when hotplug events happen, or when you manually +remove/rescan the devices. 2. Type ------- |