This patchset builds upon Yicong's previous patches [1].
Patch 2 introducing fix race issues found by using TMC-ETR.
Patch 1 & 3 introducing two cleanups found when debugging the issues.
[1] https://lore.kernel.org/linux-arm-kernel/20241202092419.11777-1-yangyicong@…
---
Changes in v4:
- a) Add comment at the context of set etr to sysfs mode.
- b) Move the check on drvdata->read to the start of enable etr.
- c) Add checks to prevent multiple sysfs processes from simultaneously
competing to enable ETR.
- d) Fix the issue with the guard used.
Link: https://lore.kernel.org/linux-arm-kernel/20250818080600.418425-1-hejunhao3@…
---
Changes in v3:
- Patches 1: Additional comment for tmc_drvdata::etr_mode. Update
comment for tmc_drvdata::reading with Jonathan's Tag.
- Patches 2: Replace scoped_guard with guard with Jonathan's Tag.
- Patches 2: Fix spinlock to raw_spinlock, and refactor this code based
on Leo's suggested solution.
- Patches 3: change the size's type to ssize_t and use max_t to simplify
the code with Leo's Tag.
Link: https://lore.kernel.org/linux-arm-kernel/20250620075412.952934-1-hejunhao3@…
Changes in v2:
- Updated the commit of patch2.
- Rebase to v6.16-rc1
Junhao He (1):
coresight: tmc: refactor the tmc-etr mode setting to avoid race
conditions
Yicong Yang (2):
coresight: tmc: Add missing doc including reading and etr_mode of
struct tmc_drvdata
coresight: tmc: Decouple the perf buffer allocation from sysfs mode
.../hwtracing/coresight/coresight-tmc-etr.c | 136 +++++++++---------
drivers/hwtracing/coresight/coresight-tmc.h | 2 +
2 files changed, 66 insertions(+), 72 deletions(-)
--
2.33.0
Do some cleanups then expand the timestamp format attribute from 1 bit
to 4 bits for ETMv4 in Perf mode. The current interval is too high for
most use cases, and particularly on the FVP the number of timestamps
generated is excessive. This change not only still allows disabling or
enabling timestamps, but also allows the interval to be configured.
The old bit is kept deprecated and undocumented for now. There are known
broken versions of Perf that don't read the format attribute positions
from sysfs and instead hard code the timestamp bit. We can leave the old
bit in the driver until we need the bit for another feature or enough
time has passed that these old Perfs are unlikely to be used.
The interval option is added as an event format attribute, rather than a
Coresight config because it's something that the driver is already
configuring automatically in Perf mode using any unused counter, so it's
not possible to modify this with a config.
Applies to coresight/next
Signed-off-by: James Clark <james.clark(a)linaro.org>
---
Changes in v4:
- Add #defines for true and false resources ETM_RES_SEL_TRUE/FALSE
- Reword comment about finding a counter to say if there are no
resources there are no counters.
- Extend existing timestamp format attribute instead of adding a new one
- Refactor all the config definitions and parsing to use
GEN_PMU_FORMAT_ATTR()/ATTR_CFG_GET_FLD() so we can see where the
unused bits are.
- Link to v3: https://lore.kernel.org/r/20251002-james-cs-syncfreq-v3-0-fe5df2bf91d1@lina…
Changes in v3:
- Move the format attr definitions to coresight-etm-perf.h we can
compile on arm32 without #ifdefs - (Leo)
- Convert the new #ifdefs to a single one in an is_visible() function so
that the code is cleaner - (Leo)
- Drop the change to remove the holes in struct etmv4_config as they
were grouped by function - (Mike)
- Link to v2: https://lore.kernel.org/r/20250814-james-cs-syncfreq-v2-0-c76fcb87696d@lina…
Changes in v2:
- Only show the attribute for ETMv4 to improve usability and fix the
arm32 build error. Wrapping everything in
IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) isn't ideal, but the -perf.c
file is shared between ETMv3 and ETMv4, and there is already precedent
for doing it this way.
- Link to v1: https://lore.kernel.org/r/20250811-james-cs-syncfreq-v1-0-b001cd6e3404@lina…
---
James Clark (13):
coresight: Change syncfreq to be a u8
coresight: Repack struct etmv4_drvdata
coresight: Refactor etm4_config_timestamp_event()
coresight: Hide unused ETMv3 format attributes
coresight: Define format attributes with GEN_PMU_FORMAT_ATTR()
coresight: Interpret ETMv3 config with ATTR_CFG_GET_FLD()
coresight: Don't reject unrecognized ETMv3 format attributes
coresight: Interpret perf config with ATTR_CFG_GET_FLD()
coresight: Interpret ETMv4 config with ATTR_CFG_GET_FLD()
coresight: Remove misleading definitions
coresight: Extend width of timestamp format attribute
coresight: Allow setting the timestamp interval
coresight: docs: Document etm4x timestamp interval option
Documentation/trace/coresight/coresight.rst | 15 +-
drivers/hwtracing/coresight/coresight-etm-perf.c | 59 +++++---
drivers/hwtracing/coresight/coresight-etm-perf.h | 39 +++++
drivers/hwtracing/coresight/coresight-etm3x-core.c | 36 ++---
drivers/hwtracing/coresight/coresight-etm4x-core.c | 164 +++++++++++++--------
drivers/hwtracing/coresight/coresight-etm4x.h | 62 +++++---
include/linux/coresight-pmu.h | 24 ---
7 files changed, 247 insertions(+), 152 deletions(-)
---
base-commit: efdccf6a511891db037e08f1351e72eaa101021e
change-id: 20250724-james-cs-syncfreq-7c2257a38ed3
Best regards,
--
James Clark <james.clark(a)linaro.org>
All CoreSight compliant components have an implementation defined number
of 0 to 8 claim tag bits in the claim tag registers.
These are used to claim the CoreSight resources by system agents.
ARM recommends implementions have 4 claim tag registers.
The CoreSight drivers implement a 2 claim tag bit protocol to allow
self hosted and external debug agents to manage access to the hardware.
However, if there are less than 2 claim tags available the protocol
incorrectly returns an error on device claim, as no checks are made.
If insufficient claim tags are present in a component then the protocol
must return success on claim / disclaim to allow components to be used
normally.
Changes read the CLAIMSET bits to establish the number of available tags,
and adjust the claim returns accordingly.
Cache the claimtag protocol availablity in the coresight_device to reduce
reads for the main claim/disclaim api.
changes since v1:
1) Added claim tag availability cache into coresight_device when using the
main coresight_claim_device() / coresight_disclaim_device() API.
Applies to coresight/next
Mike Leach (1):
coresight: fix issue where coresight component has no claimtags
drivers/hwtracing/coresight/coresight-core.c | 46 ++++++++++++++++++--
drivers/hwtracing/coresight/coresight-priv.h | 10 +++++
include/linux/coresight.h | 15 +++++++
3 files changed, 68 insertions(+), 3 deletions(-)
--
2.32.0
On 14/11/2025 5:02 am, Randy Dunlap wrote:
>
>
> On 11/12/25 7:22 AM, James Clark wrote:
>> Document how the new field is used, maximum value and the interaction
>> with SYNC timestamps.
>>
>> Signed-off-by: James Clark <james.clark(a)linaro.org>
>> ---
>> Documentation/trace/coresight/coresight.rst | 15 +++++++++++++--
>> 1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/trace/coresight/coresight.rst b/Documentation/trace/coresight/coresight.rst
>> index 806699871b80..80b5ed09d69b 100644
>> --- a/Documentation/trace/coresight/coresight.rst
>> +++ b/Documentation/trace/coresight/coresight.rst
>> @@ -613,8 +613,19 @@ They are also listed in the folder /sys/bus/event_source/devices/cs_etm/format/
>> - Session local version of the system wide setting: :ref:`ETM_MODE_RETURNSTACK
>> <coresight-return-stack>`
>> * - timestamp
>> - - Session local version of the system wide setting: :ref:`ETMv4_MODE_TIMESTAMP
>> - <coresight-timestamp>`
>> + - Controls generation and interval of timestamps.
>> +
>> + 0 = off, 1 = maximum interval .. 15 = minimum interval.
>> +
>> + Values 1 - 14 use a counter that decrements every cycle to generate a
>> + timestamp on underflow. The reload value for the counter is 2 raised to
>> + the power of timestamp interval - 1. If the value is 1 then the reload
>> + value is 1, if the value is 11 then the reload value is 1024 etc.
>
> value = 11: 2^11-1 = 2047
>
> Maybe add some parens?
>
>
Will do. I had them but I removed them because it was in a sentence so
it made it look like a side note. I think I'll change from words to symbols:
The reload value for the counter is 2 ^ (interval - 1).
Thanks
James
This patch series adds support for the Qualcomm CoreSight Interconnect TNOC
(Trace Network On Chip) block, which acts as a CoreSight graph link forwarding
trace data from subsystems to the Aggregator TNOC. Unlike the Aggregator TNOC,
this block does not support aggregation or ATID assignment.
Signed-off-by: Yuanfang Zhang <yuanfang.zhang(a)oss.qualcomm.com>
---
Changes in v5:
- Add the missing review-by tag for patch 3.
- Link to v4: https://lore.kernel.org/r/20250831-itnoc-v4-0-f0fb0ef822a5@oss.qualcomm.com
Changes in v4:
- Fix unintended blank line removals in trace_noc_enable_hw.
- Link to v3: https://lore.kernel.org/r/20250828-itnoc-v3-0-f1b55dea7a27@oss.qualcomm.com
Changes in v3:
- Add detail for changes in V2.
- Remove '#address-cells' and '#size-cells' properties from in-ports field.
- Fix comment indentation for packet description.
- Link to v2: https://lore.kernel.org/r/20250819-itnoc-v2-0-2d0e6be44e2f@oss.qualcomm.com
Changes in v2:
- Removed the trailing '|' after the description in qcom,coresight-itnoc.yaml.
- Dropped the 'select' section from the YAML file.
- Updated node name to use a more generic naming convention.
- Removed the 'items' property from the compatible field.
- Deleted the description for the reg property.
- Dropped clock-names and adjusted the order of clock-names and clocks.
- Moved additionalProperties to follow the $ref of out-ports.
- Change "atid" type from u32 to int, set it as "-EOPNOTSUPP" for non-AMBA device.
- Link to v1: https://lore.kernel.org/r/20250815-itnoc-v1-0-62c8e4f7ad32@oss.qualcomm.com
---
Yuanfang Zhang (3):
dt-bindings: arm: qcom: Add Coresight Interconnect TNOC
coresight-tnoc: add platform driver to support Interconnect TNOC
coresight-tnoc: Add runtime PM support for Interconnect TNOC
.../bindings/arm/qcom,coresight-itnoc.yaml | 90 ++++++++++++++
drivers/hwtracing/coresight/coresight-tnoc.c | 136 +++++++++++++++++++--
2 files changed, 215 insertions(+), 11 deletions(-)
---
base-commit: 2b52cf338d39d684a1c6af298e8204902c026aca
change-id: 20250815-itnoc-460273d1b80c
Best regards,
--
Yuanfang Zhang <yuanfang.zhang(a)oss.qualcomm.com>
This series is extracted from [1], focusing on CoreSight path power
management.
Compared to the previous version, this series is updated heavily for:
1) Dropped the global per CPU variable for saving path pointers.
Instead, the activate path is now stored in the source device's
structure. This allows fetching the path pointer naturally based on
the source regardless of whether it is a per-CPU source or a system
source (such as STM).
This improvement addresses Mike's comment that, later we can polish
coresight-sysfs.c to remove the tracer_path variables.
2) To simplify the series and make it easier to review, the CTI driver
related fixes have been removed from this series and which will be
sent out separately.
3) This series disables the path when a CPU is hot-plugged off but does
not re-enable it when the CPU is subsequently hot-plugged in. This
simplifies the implementation and keep it consistent with the perf
session's behavior.
It also improves security, as there is no risk of unintended tracing
caused by a CPU being hot-plugged after a long period of inactivity.
This series is dependent on ETM driver's PM improvement series [2] and
has been verified on Juno-r2 and FVP RevC.
[1] https://lore.kernel.org/linux-arm-kernel/20250915-arm_coresight_power_manag…
[2] https://lore.kernel.org/linux-arm-kernel/20251103-arm_coresight_power_manag…
---
Changes in v4:
- Changed to store path pointer in coresight_device, this is easier for
fetching path pointer based on source device (Mike).
- Dropped changes in CTI driver.
- Only disabled path for CPU hot-plugged off but not enable path for
hot-plugged in.
- Removed James' test tags for modified patches.
- Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-…
Signed-off-by: Leo Yan <leo.yan(a)arm.com>
---
Leo Yan (14):
coresight: sysfs: Validate CPU online status for per-CPU sources
coresight: Set per CPU source pointer
coresight: Register CPU PM notifier in core layer
coresight: etm4x: Hook CPU PM callbacks
coresight: Add callback to determine if PM is needed
coresight: etm4x: Remove redundant condition checks in save and restore
coresight: syscfg: Use spinlock to protect active variables
coresight: Introduce coresight_enable_source() helper
coresight: Save activated path into source device
coresight: Add 'in_idle' argument to enable/disable path functions
coresight: Control path during CPU idle
coresight: Add PM callbacks for percpu sink
coresight: Take hotplug lock in enable_source_store() for Sysfs mode
coresight: Move CPU hotplug callbacks to core layer
Yabin Cui (1):
coresight: trbe: Save and restore state across CPU low power state
drivers/hwtracing/coresight/coresight-catu.c | 1 +
drivers/hwtracing/coresight/coresight-core.c | 273 ++++++++++++++++++++-
drivers/hwtracing/coresight/coresight-ctcu-core.c | 1 +
drivers/hwtracing/coresight/coresight-cti-core.c | 1 +
drivers/hwtracing/coresight/coresight-dummy.c | 1 +
drivers/hwtracing/coresight/coresight-etb10.c | 1 +
drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
drivers/hwtracing/coresight/coresight-etm3x-core.c | 1 +
drivers/hwtracing/coresight/coresight-etm4x-core.c | 137 ++---------
drivers/hwtracing/coresight/coresight-funnel.c | 1 +
drivers/hwtracing/coresight/coresight-priv.h | 3 +
drivers/hwtracing/coresight/coresight-replicator.c | 1 +
drivers/hwtracing/coresight/coresight-stm.c | 1 +
drivers/hwtracing/coresight/coresight-syscfg.c | 22 +-
drivers/hwtracing/coresight/coresight-syscfg.h | 2 +
drivers/hwtracing/coresight/coresight-sysfs.c | 12 +-
drivers/hwtracing/coresight/coresight-tmc-core.c | 1 +
drivers/hwtracing/coresight/coresight-tnoc.c | 2 +
drivers/hwtracing/coresight/coresight-tpda.c | 1 +
drivers/hwtracing/coresight/coresight-tpdm.c | 1 +
drivers/hwtracing/coresight/coresight-tpiu.c | 1 +
drivers/hwtracing/coresight/coresight-trbe.c | 85 ++++++-
drivers/hwtracing/coresight/ultrasoc-smb.c | 1 +
include/linux/coresight.h | 13 +
24 files changed, 425 insertions(+), 140 deletions(-)
---
base-commit: f9ac95561513e18c2a2cf8905355dc5f0e030c46
change-id: 20251104-arm_coresight_path_power_management_improvement-dab4966f8280
Best regards,
--
Leo Yan <leo.yan(a)arm.com>
This series is extracted from the CoreSight power management fixes and
refactoring [1], focusing on ETMv3/4 power management.
This series has been verified on Juno-r2 platform.
[1] https://lore.kernel.org/linux-arm-kernel/20250915-arm_coresight_power_manag…
---
Changes in v6:
- Added a 'retain_ss_status' flag to indicate if need to restain
single-shot status (Suzuki).
- Introduced __etm4_disable_hw() without calling
etm4_cs_{unlock|lock}() pairs, which is convenient for the save
callback (Suzuki).
- Link to v5: https://lore.kernel.org/r/20251103-arm_coresight_power_management_fix-v5-0-…
Changes in v5:
- Added more info for removing redundant DSB in
etm4_{enable|disable}_trace_unit() (Suzuki/Levi).
- Dropped moving isb() out from etm4_{enable|disable}_trace_unit()
(Suzuki).
- Reordered patches to move fixes earlier.
- Link to v4: https://lore.kernel.org/r/20251024-arm_coresight_power_management_fix-v4-0-…
Changes in v4:
- Added patch 10 for retaining sequencer state in ETMv4 driver (Mike).
- Added Mike's review tags.
- Added James' test tags.
- Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-…
Changes in v3:
- Fixed building failure in ETMv3 driver (kernel test robot).
- Refactoring ETMv3 change for checking CPU ID (Levi).
- Fixed NULL pointer issue during CPU idle (James).
- Fixed lockdep complaint for HARDIRQ-safe and HARDIRA-unsafe (James).
- Fixed acquiring mutex in atomic context (James).
- Rebased on the latest coresight-next branch.
- Link to v2: https://lore.kernel.org/r/20250701-arm_cs_pm_fix_v3-v2-0-23ebb864fcc1@arm.c…
Changes in v2:
- Refactored ETMv4 suspend and resume for reusing the normal enabling
and disabling flows (James).
- Used a per-CPU structure to maintain path pointers (James).
- Supported helpers in CPU PM flows (James).
- Fixed the SMP-safe access to device mode.
- Fixed the context synchronization in ETMv4x driver.
- Link to v1: https://lore.kernel.org/linux-arm-kernel/20250516160742.1200904-1-leo.yan@a…
Signed-off-by: Leo Yan <leo.yan(a)arm.com>
---
Leo Yan (11):
coresight: Change device mode to atomic type
coresight: etm4x: Always set tracer's device mode on target CPU
coresight: etm3x: Always set tracer's device mode on target CPU
coresight: etm4x: Correct polling IDLE bit
coresight: etm4x: Add context synchronization before enabling trace
coresight: etm4x: Properly control filter in CPU idle with FEAT_TRF
coresight: etm4x: Remove the redundant DSB
coresight: etm4x: Remove the state_needs_restore flag
coresight: etm4x: Add flag to retain single-shot status
coresight: etm4x: Retain sequencer state
coresight: etm4x: Reuse normal enable and disable logic in CPU idle
drivers/hwtracing/coresight/coresight-etm3x-core.c | 59 ++--
drivers/hwtracing/coresight/coresight-etm4x-core.c | 358 +++++++--------------
drivers/hwtracing/coresight/coresight-etm4x.h | 64 +---
include/linux/coresight.h | 25 +-
4 files changed, 172 insertions(+), 334 deletions(-)
---
base-commit: b139702a889692ec30702534ebb1ae2b11ed1cbf
change-id: 20250909-arm_coresight_power_management_fix-139873f942e8
Best regards,
--
Leo Yan <leo.yan(a)arm.com>
On 11/12/25 01:24, Ma Ke wrote:
> @@ -454,6 +454,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
> goto err;
>
> out:
> + if (user_sink) {
> + put_device(&user_sink->dev);
> + user_sink = NULL;
> + }
After searched kernel, I prefer to put device in coresight_get_sink_by_id().
Please refer acpi_dev_present() how to do that.
I would like Suzuki's confirmation in case I introduce noise.
Thanks,
Leo
This series is extracted from the CoreSight power management fixes and
refactoring [1], focusing on ETMv3/4 power management.
This series has been verified on Juno-r2 platform.
[1] https://lore.kernel.org/linux-arm-kernel/20250915-arm_coresight_power_manag…
---
Changes in v7:
- Updated the commit log in patch 11 (Mike).
- Link to v6: https://lore.kernel.org/r/20251111-arm_coresight_power_management_fix-v6-0-…
Changes in v6:
- Added a 'retain_ss_status' flag to indicate if need to restain
single-shot status (Suzuki).
- Introduced __etm4_disable_hw() without calling
etm4_cs_{unlock|lock}() pairs, which is convenient for the save
callback (Suzuki).
- Link to v5: https://lore.kernel.org/r/20251103-arm_coresight_power_management_fix-v5-0-…
Changes in v5:
- Added more info for removing redundant DSB in
etm4_{enable|disable}_trace_unit() (Suzuki/Levi).
- Dropped moving isb() out from etm4_{enable|disable}_trace_unit()
(Suzuki).
- Reordered patches to move fixes earlier.
- Link to v4: https://lore.kernel.org/r/20251024-arm_coresight_power_management_fix-v4-0-…
Changes in v4:
- Added patch 10 for retaining sequencer state in ETMv4 driver (Mike).
- Added Mike's review tags.
- Added James' test tags.
- Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-…
Changes in v3:
- Fixed building failure in ETMv3 driver (kernel test robot).
- Refactoring ETMv3 change for checking CPU ID (Levi).
- Fixed NULL pointer issue during CPU idle (James).
- Fixed lockdep complaint for HARDIRQ-safe and HARDIRA-unsafe (James).
- Fixed acquiring mutex in atomic context (James).
- Rebased on the latest coresight-next branch.
- Link to v2: https://lore.kernel.org/r/20250701-arm_cs_pm_fix_v3-v2-0-23ebb864fcc1@arm.c…
Changes in v2:
- Refactored ETMv4 suspend and resume for reusing the normal enabling
and disabling flows (James).
- Used a per-CPU structure to maintain path pointers (James).
- Supported helpers in CPU PM flows (James).
- Fixed the SMP-safe access to device mode.
- Fixed the context synchronization in ETMv4x driver.
- Link to v1: https://lore.kernel.org/linux-arm-kernel/20250516160742.1200904-1-leo.yan@a…
Signed-off-by: Leo Yan <leo.yan(a)arm.com>
---
Leo Yan (11):
coresight: Change device mode to atomic type
coresight: etm4x: Always set tracer's device mode on target CPU
coresight: etm3x: Always set tracer's device mode on target CPU
coresight: etm4x: Correct polling IDLE bit
coresight: etm4x: Add context synchronization before enabling trace
coresight: etm4x: Properly control filter in CPU idle with FEAT_TRF
coresight: etm4x: Remove the redundant DSB
coresight: etm4x: Remove the state_needs_restore flag
coresight: etm4x: Add flag to retain single-shot status
coresight: etm4x: Retain sequencer state
coresight: etm4x: Reuse normal enable and disable logic in CPU idle
drivers/hwtracing/coresight/coresight-etm3x-core.c | 59 ++--
drivers/hwtracing/coresight/coresight-etm4x-core.c | 358 +++++++--------------
drivers/hwtracing/coresight/coresight-etm4x.h | 64 +---
include/linux/coresight.h | 25 +-
4 files changed, 172 insertions(+), 334 deletions(-)
---
base-commit: b139702a889692ec30702534ebb1ae2b11ed1cbf
change-id: 20250909-arm_coresight_power_management_fix-139873f942e8
Best regards,
--
Leo Yan <leo.yan(a)arm.com>
Hi
On 11/11/2025 14:42, Ma Ke wrote:
> In etm_setup_aux(), when a user sink is obtained via
> coresight_get_sink_by_id(), it increments the reference count of the
> sink device. However, if the sink is used in path building, the path
> holds a reference, but the initial reference from
> coresight_get_sink_by_id() is not released, causing a reference count
> leak. We should release the initial reference after the path is built.
>
> Found by code review.
>
> Cc: stable(a)vger.kernel.org
> Fixes: 0e6c20517596 ("coresight: etm-perf: Allow an event to use different sinks")
> Signed-off-by: Ma Ke <make24(a)iscas.ac.cn>
> ---
> drivers/hwtracing/coresight/coresight-etm-perf.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index f677c08233ba..6584f6aa87bf 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -453,6 +453,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
> if (!event_data->snk_config)
> goto err;
>
> + if (user_sink) {
> + put_device(&user_sink->dev);
> + user_sink = NULL;
> + }
> +
I would recommend moving this to the out: label below, to make sure
we drop the refcount even in the error path.
Otherwise looks good to me.
Suzuki
> out:
> return event_data;
>