CoreSight March 2026

coresight@lists.linaro.org

7 participants
20 discussions

[PATCH v7 00/20] CoreSight: Refactor power management for CoreSight path

by Leo Yan

This series focuses on CoreSight path power management. The changes can be divided into four parts for review: Patches 01~07: Refactor the CPU idle flow with moving common code into the CoreSight core layer. Patches 08~15: Refactor path enabling and disabling with range, add path control during CPU idle. Patches 16~17: Support the sink (TRBE) control during CPU idle. Patches 18~20: Move the CPU hotplug flow into the coresight core layer and simplify the code. This series is rebased on the coresight-next branch and has been verified on Juno-r2 (ETM + ETR) and FVP RevC (ETE + TRBE). --- Changes in v7: - Added a flag in coresight_desc to indicate CPU bound device (Suzuki). - Used coresight_mutex to protect per-CPU source pointer (Suzuki). - Added a spinlock for exclusive access per-CPU source pointer (Suzuki). - Dropped .pm_is_needed() callback (Suzuki). - Supported range in path enabling / disabling (Suzuki). - Gathered test and review tags (Levi / James). - Link to v6: https://lore.kernel.org/r/20260305-arm_coresight_path_power_management_impr… Changes in v6: - Rebase on the latest coresight-next branch. - Always save and restore TRBE context during idle (Will). - Use get_cpu() / put_cpu() when set the per CPU source pointer. - Link to v5: https://lore.kernel.org/r/20251119-arm_coresight_path_power_management_impr… Changes in v5: - Set the per-CPU source pointer on target CPU (Suzuki). - Reused existed enable/disable buffer functions in TRBE callbacks (James). - Refactored refcount for source devices in SysFS mode. - Released path in cpu-hotplug off flow to avoid memory leak. - Updated ETMv3 driver when move common code into core layer. - Rebased on the latest coresight-next branch. - Link to v4: https://lore.kernel.org/r/20251104-arm_coresight_path_power_management_impr… Signed-off-by: Leo Yan <leo.yan(a)arm.com> --- Leo Yan (19): coresight: Populate CPU ID into coresight_device coresight: Remove .cpu_id() callback from source ops coresight: sysfs: Validate CPU online status for per-CPU sources coresight: Move per-CPU source pointer to core layer coresight: Register CPU PM notifier in core layer coresight: etm4x: Hook CPU PM callbacks 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 active path for system tracers coresight: etm4x: Set active path on target CPU coresight: etm3x: Set active path on target CPU coresight: sysfs: Use source's path pointer for path control coresight: Control path with range coresight: Control path during CPU idle coresight: Add PM callbacks for sink device coresight: sysfs: Increment refcount only for system tracers 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 | 2 +- drivers/hwtracing/coresight/coresight-core.c | 377 +++++++++++++++++++-- drivers/hwtracing/coresight/coresight-cti-core.c | 9 +- drivers/hwtracing/coresight/coresight-etm-perf.c | 25 +- drivers/hwtracing/coresight/coresight-etm3x-core.c | 73 +--- drivers/hwtracing/coresight/coresight-etm4x-core.c | 154 ++------- drivers/hwtracing/coresight/coresight-priv.h | 4 + drivers/hwtracing/coresight/coresight-syscfg.c | 21 +- drivers/hwtracing/coresight/coresight-syscfg.h | 2 + drivers/hwtracing/coresight/coresight-sysfs.c | 126 +++---- drivers/hwtracing/coresight/coresight-trbe.c | 61 +++- include/linux/coresight.h | 15 +- 12 files changed, 546 insertions(+), 323 deletions(-) --- base-commit: a90863095f84f6d17c49716e4e2212d28a6b25b5 change-id: 20251104-arm_coresight_path_power_management_improvement-dab4966f8280 Best regards, -- Leo Yan <leo.yan(a)arm.com>

21 hours, 9 minutes

Re: [PATCH] coresight: platform: check the availability of the endpoint before parse

by Leo Yan

Hi Jie, On Fri, Mar 20, 2026 at 04:44:54PM +0800, Jie Gan wrote: [...] > It's about the coresight_find_device_by_fwnode() returns NULL, resulting in > -EPROBE_DEFER. So the probe process will re-start after several seconds, but > always failed because we have a "disabled" device node in DT(we can see this > device in DT, but it never becomes available). It's ok if the device only > has one remote device, but has issue with more than one remote devices. > > Consider below situation: > > device0 > | | > device1 device2(status = "disabled") > > The probe of device0 succeeds only when device1 and device2 are available at > probe time. But I think it's ok to probe the device0 only with device1 > available. Thanks a lot for details. We might need to report warning or error if all remote endpoints fail (e.g., device1/device2 both are disabled), this is a rare case so would be low priority. For this patch: Reviewed-by: Leo Yan <leo.yan(a)arm.com>

1 day, 5 hours

Re: [PATCH] coresight: platform: check the availability of the endpoint before parse

by Leo Yan

On Fri, Mar 20, 2026 at 03:31:12PM +0800, Jie Gan wrote: > Check endpoint availability before parsing it. If parsing a connected > endpoint fails, the probe is deferred until the endpoint becomes > available, or eventually fails. I want to clarify a bit the failure flow. Does this mean coresight_find_device_by_fwnode() returns NULL when the remote device is not found, resulting in -EPROBE_DEFER, but the probe never waits for the remote device to become available? > In some legacy cases, a replicator > has two output ports where one is disabled and the other is available. > The replicator probe always fails because the disabled endpoint never > becomes available for parsing. In addition, there is no need to defer > probing a device that is connected to a disabled device, which improves > probe performance. > > Signed-off-by: Jie Gan <jie.gan(a)oss.qualcomm.com> > --- > drivers/hwtracing/coresight/coresight-platform.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c > index 0ca3bd762454..e337b6e2bf32 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -220,6 +220,8 @@ static int of_coresight_parse_endpoint(struct device *dev, > rparent = of_coresight_get_port_parent(rep); > if (!rparent) > break; > + if (!of_device_is_available(rparent)) > + break; > if (of_graph_parse_endpoint(rep, &rendpoint)) > break; > > > --- > base-commit: b5d083a3ed1e2798396d5e491432e887da8d4a06 > change-id: 20260320-add-availability-check-4cb2ee6e520b > > Best regards, > -- > Jie Gan <jie.gan(a)oss.qualcomm.com> >

1 day, 6 hours

[PATCH 0/2] perf: tools: cs-etm: Fixes for CoreSight debug dump

by Mike Leach

perf will output additional CoreSight debug information, from the 'perf report --dump' command, when the build option CSTRACE_RAW=1 is added to the usual CORESIGHT=1 at build time. This additional information consists of raw trace data in the form of CoreSight formatted trace frames. This is intended to be used to investigate possible issues relating to trace data corruption, trace hardware issues or problems with decode. The CoreSight formatted trace frames are used when multiple ETMs trace into an ETR, and not present when a single ETE traces into the TRBE. When the build option is used and perf is used to dump an ETE/TRBE generated buffer a segfault will occur in the OpenCSD library. Patch 1 of this set removes the unnecessary call to print the raw trace frames when not needed, and fixes the segfault where older versions of OpenCSD are in use. Patch 2 enhances the debug output to associate raw data with individual packets, which means that raw data is now present for ETE and extended for ETM. OpenCSD is being fixed independently. Mike Leach (2): perf: tools: cs-etm: Fix print issue for Coresight debug in ETE/TRBE trace perf: tools: cs-etm: Enhance raw Coresight trace debug display tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) -- 2.43.0

3 days, 1 hour

[PATCH v2 1/2] perf: tools: cs-etm: Fix print issue for Coresight debug in ETE/TRBE trace

by Mike Leach

Building perf with CORESIGHT=1 and the optional CSTRACE_RAW=1 enables additional debug printing of raw trace data when using command:- perf report --dump. This raw trace prints the CoreSight formatted trace frames, which may be used to investigate suspected issues with trace quality / corruption / decode. These frames are not present in ETE + TRBE trace. This fix removes the unnecessary call to print these frames. This fix also rationalises implementation - original code had helper function that unnecessarily repeated initialisation calls that had already been made. Due to an addtional fault with the OpenCSD library, this call when ETE/TRBE are being decoded will cause a segfault in perf. This fix also prevents that problem for perf using older (<= 1.8.0 version) OpenCSD libraries. Fixes: 68ffe3902898 ("perf tools: Add decoder mechanic to support dumping trace data") Reported-by: Leo Yan <leo.yan(a)arm.com> Signed-off-by: Mike Leach <mike.leach(a)arm.com> --- Changes in v2: Rationalise implementation --- .../perf/util/cs-etm-decoder/cs-etm-decoder.c | 51 +++++-------------- 1 file changed, 13 insertions(+), 38 deletions(-) diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c index 3050fe212666..8592a778b26a 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -237,46 +237,24 @@ cs_etm_decoder__init_def_logger_printing(struct cs_etm_decoder_params *d_params, (void *)decoder, cs_etm_decoder__print_str_cb); if (ret != 0) - ret = -1; - - return 0; -} + return -1; #ifdef CS_LOG_RAW_FRAMES -static void -cs_etm_decoder__init_raw_frame_logging(struct cs_etm_decoder_params *d_params, - struct cs_etm_decoder *decoder) -{ - /* Only log these during a --dump operation */ - if (d_params->operation == CS_ETM_OPERATION_PRINT) { - /* set up a library default logger to process the - * raw frame printer we add later - */ - ocsd_def_errlog_init(OCSD_ERR_SEV_ERROR, 1); - - /* no stdout / err / file output */ - ocsd_def_errlog_config_output(C_API_MSGLOGOUT_FLG_NONE, NULL); - - /* set the string CB for the default logger, - * passes strings to perf print logger. - */ - ocsd_def_errlog_set_strprint_cb(decoder->dcd_tree, - (void *)decoder, - cs_etm_decoder__print_str_cb); - + /* + * Only log raw frames if --dump operation and hardware is actually + * generating formatted CoreSight trace frames + */ + if ((d_params->operation == CS_ETM_OPERATION_PRINT) && + (d_params->formatted == true)) { /* use the built in library printer for the raw frames */ - ocsd_dt_set_raw_frame_printer(decoder->dcd_tree, - CS_RAW_DEBUG_FLAGS); + ret = ocsd_dt_set_raw_frame_printer(decoder->dcd_tree, + CS_RAW_DEBUG_FLAGS); + if (ret != 0) + return -1; } -} -#else -static void -cs_etm_decoder__init_raw_frame_logging( - struct cs_etm_decoder_params *d_params __maybe_unused, - struct cs_etm_decoder *decoder __maybe_unused) -{ -} #endif + return 0; +} static ocsd_datapath_resp_t cs_etm_decoder__do_soft_timestamp(struct cs_etm_queue *etmq, @@ -738,9 +716,6 @@ cs_etm_decoder__new(int decoders, struct cs_etm_decoder_params *d_params, if (ret != 0) goto err_free_decoder; - /* init raw frame logging if required */ - cs_etm_decoder__init_raw_frame_logging(d_params, decoder); - for (i = 0; i < decoders; i++) { ret = cs_etm_decoder__create_etm_decoder(d_params, &t_params[i], -- 2.43.0

3 days, 4 hours

[PATCH v6 00/19] CoreSight: Refactor power management for CoreSight path

by Leo Yan

This series focuses on CoreSight path power management. The changes can be divided into four parts for review: Patches 01~06: Refactor the CPU idle flow with moving common code into the CoreSight core layer. Patches 07~14: Add link control during CPU idle. Patches 15~16: Support the sink (TRBE) control during CPU idle. Patches 17~19: Move the CPU hotplug flow into the coresight core layer and simplify the code. This series is rebased on the coresight-next branch and has been verified on Juno-r2 and FVP RevC. --- Changes in v6: - Rebase on the latest coresight-next branch. - Always save and restore TRBE context during idle (Will). - Use get_cpu() / put_cpu() when set the per CPU source pointer. - Link to v5: https://lore.kernel.org/r/20251119-arm_coresight_path_power_management_impr… Changes in v5: - Set the per-CPU source pointer on target CPU (Suzuki). - Reused existed enable/disable buffer functions in TRBE callbacks (James). - Refactored refcount for source devices in SysFS mode. - Released path in cpu-hotplug off flow to avoid memory leak. - Updated ETMv3 driver when move common code into core layer. - Rebased on the latest coresight-next branch. - Link to v4: https://lore.kernel.org/r/20251104-arm_coresight_path_power_management_impr… 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 (18): 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 active path for system tracers coresight: etm4x: Set active path on target CPU coresight: etm3x: Set active path on target CPU coresight: sysfs: Use source's path pointer for path control coresight: Add 'in_idle' argument to path coresight: Control path during CPU idle coresight: Add PM callbacks for sink device coresight: sysfs: Increment refcount only for system tracers 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 | 65 ++--- drivers/hwtracing/coresight/coresight-etm4x-core.c | 153 +++--------- 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 | 126 +++------- 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 | 60 ++++- drivers/hwtracing/coresight/ultrasoc-smb.c | 1 + include/linux/coresight.h | 11 + 24 files changed, 458 insertions(+), 274 deletions(-) --- base-commit: 9c5ef7a30d9044f8706bd02bfdc4eff7266f3e25 change-id: 20251104-arm_coresight_path_power_management_improvement-dab4966f8280 Best regards, -- Leo Yan <leo.yan(a)arm.com>

4 days, 3 hours

Re: [PATCH v15 2/7] coresight: tmc: add create/clean functions for etr_buf_list

by Suzuki K Poulose

On 13/03/2026 09:02, Jie Gan wrote: > Introduce functions for creating and inserting or removing the > etr_buf_node to/from the etr_buf_list. > > The byte-cntr functionality requires two etr_buf to receive trace data. > The active etr_buf collects the trace data from source device, while the > byte-cntr reading function accesses the deactivated etr_buf after is > has been filled and synced, transferring data to the userspace. > > Reviewed-by: Mike Leach <mike.leach(a)linaro.org> > Signed-off-by: Jie Gan <jie.gan(a)oss.qualcomm.com> > --- > drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + > drivers/hwtracing/coresight/coresight-tmc-etr.c | 108 +++++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-tmc.h | 17 ++++ > 3 files changed, 126 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index c89fe996af23..bac3278ef4dd 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -835,6 +835,7 @@ static int __tmc_probe(struct device *dev, struct resource *res) > idr_init(&drvdata->idr); > mutex_init(&drvdata->idr_mutex); > dev_list = "tmc_etr"; > + INIT_LIST_HEAD(&drvdata->etr_buf_list); > break; > case TMC_CONFIG_TYPE_ETF: > desc.groups = coresight_etf_groups; > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index 4dc1defe27a5..fdf23e1c932f 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -1918,6 +1918,114 @@ const struct coresight_ops tmc_etr_cs_ops = { > .panic_ops = &tmc_etr_sync_ops, > }; > > +/** > + * tmc_clean_etr_buf_list - clean the etr_buf_list. > + * @drvdata: driver data of the TMC device. > + * > + * Remove unused buffers from @drvdata->etr_buf_list and free them. > + */ > +void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata) > +{ > + struct etr_buf_node *nd, *next; > + unsigned long flags; > + > + lockdep_assert_held(&drvdata->spinlock); > + list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, link) { > + if (nd->sysfs_buf == drvdata->sysfs_buf) { > + if (coresight_get_mode(drvdata->csdev) != CS_MODE_DISABLED) { > + /* > + * Dont free the sysfs_buf, just remove it from list. > + * drvdata->sysfs_buf will hold the buffer and free it later. > + */ > + nd->sysfs_buf = NULL; > + list_del(&nd->link); > + kfree(nd); > + continue; > + } > + } > + /* Free allocated buffers which are not utilized by ETR */ > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); This is dangerous ! Restoring the irqflags to an uninitialised value from a different function thant where it was locked. Please clean this up Suzuki > + tmc_etr_free_sysfs_buf(nd->sysfs_buf); > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + drvdata->sysfs_buf = NULL; > + nd->sysfs_buf = NULL; > + list_del(&nd->link); > + kfree(nd); > + } > +} > +EXPORT_SYMBOL_GPL(tmc_clean_etr_buf_list); > + > +/** > + * tmc_create_etr_buf_list - create a list to manage the etr_buf_node. > + * @drvdata: driver data of the TMC device. > + * @num_nodes: number of nodes want to create with the list. > + * > + * Return 0 upon success and return the error number if fail. > + */ > +int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes) > +{ > + struct etr_buf_node *new_node; > + struct etr_buf *sysfs_buf; > + unsigned long flags; > + int i = 0, ret = 0; > + > + lockdep_assert_held(&drvdata->spinlock); > + /* We dont need a list if there is only one node */ > + if (num_nodes < 2) > + return -EINVAL; > + > + /* We expect that sysfs_buf in drvdata has already been allocated. */ > + if (drvdata->sysfs_buf) { > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); > + /* Directly insert the allocated sysfs_buf into the list first */ > + new_node = kzalloc_obj(*new_node, GFP_KERNEL); > + if (IS_ERR(new_node)) > + return PTR_ERR(new_node); > + > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + new_node->sysfs_buf = drvdata->sysfs_buf; > + new_node->is_free = false; > + list_add(&new_node->link, &drvdata->etr_buf_list); > + i++; > + } > + > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); > + while (i < num_nodes) { > + new_node = kzalloc_obj(*new_node, GFP_KERNEL); > + if (IS_ERR(new_node)) { > + ret = PTR_ERR(new_node); > + break; > + } > + > + sysfs_buf = tmc_alloc_etr_buf(drvdata, drvdata->size, 0, cpu_to_node(0), NULL); > + if (IS_ERR(sysfs_buf)) { > + kfree(new_node); > + ret = PTR_ERR(sysfs_buf); > + break; > + } > + > + /* We dont have a available sysfs_buf in drvdata, setup one */ > + if (!drvdata->sysfs_buf) { > + drvdata->sysfs_buf = sysfs_buf; > + new_node->is_free = false; > + } else > + new_node->is_free = true; > + > + new_node->sysfs_buf = sysfs_buf; > + list_add(&new_node->link, &drvdata->etr_buf_list); > + i++; > + } > + > + /* Clean the list if there is an error */ > + if (ret) > + tmc_clean_etr_buf_list(drvdata); > + > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(tmc_create_etr_buf_list); > + > int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) > { > int ret = 0; > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index 319a354ede9f..81237944b986 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -208,6 +208,19 @@ struct tmc_resrv_buf { > s64 len; > }; > > +/** > + * @sysfs_buf: Allocated sysfs_buf. > + * @is_free: Indicates whether the buffer is free to choose. > + * @pos: Position of the buffer. > + * @link: list_head of the node. > + */ > +struct etr_buf_node { > + struct etr_buf *sysfs_buf; > + bool is_free; > + loff_t pos; > + struct list_head link; > +}; > + > /** > * struct tmc_drvdata - specifics associated to an TMC component > * @atclk: optional clock for the core parts of the TMC. > @@ -245,6 +258,7 @@ struct tmc_resrv_buf { > * (after crash) by default. > * @crash_mdata: Reserved memory for storing tmc crash metadata. > * Used by ETR/ETF. > + * @etr_buf_list: List that is used to manage allocated etr_buf. > */ > struct tmc_drvdata { > struct clk *atclk; > @@ -275,6 +289,7 @@ struct tmc_drvdata { > struct etr_buf *perf_buf; > struct tmc_resrv_buf resrv_buf; > struct tmc_resrv_buf crash_mdata; > + struct list_head etr_buf_list; > }; > > struct etr_buf_operations { > @@ -447,5 +462,7 @@ struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev, > enum cs_mode mode, > struct coresight_path *path); > extern const struct attribute_group coresight_etr_group; > +void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata); > +int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes); > > #endif >

4 days, 3 hours

Re: [PATCH v2] coresight: tpdm: add traceid_show for checking traceid

by Suzuki K Poulose

On 16/03/2026 10:29, Jie Gan wrote: > > Hi Suzuki, > > On 3/16/2026 5:32 PM, Suzuki K Poulose wrote: >> On 16/03/2026 07:23, Jie Gan wrote: >>> Save the trace ID in drvdata during TPDM enablement and expose it >>> to userspace to support trace data parsing. >>> >>> The TPDM device’s trace ID corresponds to the trace ID allocated >>> to the connected TPDA device. >>> >>> Signed-off-by: Jie Gan <jie.gan(a)oss.qualcomm.com> >>> --- >>> Changes in V2: >>> 1. Use sysfs_emit instead of sprintf. >>> Link to V1 - https://lore.kernel.org/all/20260306-add-traceid-show- >>> for-tpdm-v1-1-0658a8edb972(a)oss.qualcomm.com/ >> >> Why is this patch required even ? For each TPDM there is a single > > It's taking effort to retrieve the trace ID of the TPDA device because > it's not a source device. The trace ID is required to identify the > origin of the trace data and is essential for parsing the received data. > >> port in a single TPDA in the system where it can reach and that is >> fixed for a platform. Can we not get this from there ? Also, there >> is not TraceID technically for a TPDM, right ? It is all a property > > Yes, we dont allocate trace ID for a TPDM device. The TraceID is > allocated to the TPDA device. Now if you combine both your responses, don't you think they contradict each other ? Also, the TraceID we show is *not valid* if the TPDM was never enabled. So this is inconsistent, isn't it ? Unless we return an error in this case Suzuki > > Thanks, > Jie > >> of the TPDA ? >> > > >> Suzuki >> >> >>> --- >>> drivers/hwtracing/coresight/coresight-tpdm.c | 31 +++++++++++++++++ >>> + +++++++++- >>> drivers/hwtracing/coresight/coresight-tpdm.h | 2 ++ >>> 2 files changed, 32 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/ >>> hwtracing/coresight/coresight-tpdm.c >>> index da77bdaad0a4..774a63def817 100644 >>> --- a/drivers/hwtracing/coresight/coresight-tpdm.c >>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c >>> @@ -481,7 +481,7 @@ static void __tpdm_enable(struct tpdm_drvdata >>> *drvdata) >>> static int tpdm_enable(struct coresight_device *csdev, struct >>> perf_event *event, >>> enum cs_mode mode, >>> - __maybe_unused struct coresight_path *path) >>> + struct coresight_path *path) >>> { >>> struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); >>> @@ -497,6 +497,7 @@ static int tpdm_enable(struct coresight_device >>> *csdev, struct perf_event *event, >>> } >>> __tpdm_enable(drvdata); >>> + drvdata->traceid = path->trace_id; >>> drvdata->enable = true; >>> spin_unlock(&drvdata->spinlock); >>> @@ -693,6 +694,26 @@ static struct attribute_group tpdm_attr_grp = { >>> .attrs = tpdm_attrs, >>> }; >>> +static ssize_t traceid_show(struct device *dev, >>> + struct device_attribute *attr, char *buf) >>> +{ >>> + unsigned long val; >>> + struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent); >>> + >>> + val = drvdata->traceid; >>> + return sysfs_emit(buf, "%#lx\n", val); >>> +} >>> +static DEVICE_ATTR_RO(traceid); >>> + >>> +static struct attribute *traceid_attrs[] = { >>> + &dev_attr_traceid.attr, >>> + NULL, >>> +}; >>> + >>> +static struct attribute_group traceid_attr_grp = { >>> + .attrs = traceid_attrs, >>> +}; >>> + >>> static ssize_t dsb_mode_show(struct device *dev, >>> struct device_attribute *attr, >>> char *buf) >>> @@ -1367,6 +1388,12 @@ static const struct attribute_group >>> *tpdm_attr_grps[] = { >>> &tpdm_cmb_patt_grp, >>> &tpdm_cmb_msr_grp, >>> &tpdm_mcmb_attr_grp, >>> + &traceid_attr_grp, >>> + NULL, >>> +}; >>> + >>> +static const struct attribute_group *static_tpdm_attr_grps[] = { >>> + &traceid_attr_grp, >>> NULL, >>> }; >>> @@ -1425,6 +1452,8 @@ static int tpdm_probe(struct device *dev, >>> struct resource *res) >>> desc.access = CSDEV_ACCESS_IOMEM(base); >>> if (res) >>> desc.groups = tpdm_attr_grps; >>> + else >>> + desc.groups = static_tpdm_attr_grps; >> >> > drvdata->csdev = coresight_register(&desc);> if >> (IS_ERR(drvdata->csdev)) >>> return PTR_ERR(drvdata->csdev); >>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/ >>> hwtracing/coresight/coresight-tpdm.h >>> index 2867f3ab8186..befecbb896f4 100644 >>> --- a/drivers/hwtracing/coresight/coresight-tpdm.h >>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h >>> @@ -300,6 +300,7 @@ struct cmb_dataset { >>> * @cmb Specifics associated to TPDM CMB. >>> * @dsb_msr_num Number of MSR supported by DSB TPDM >>> * @cmb_msr_num Number of MSR supported by CMB TPDM >>> + * @traceid trace ID of the path. >>> */ >>> struct tpdm_drvdata { >>> @@ -313,6 +314,7 @@ struct tpdm_drvdata { >>> struct cmb_dataset *cmb; >>> u32 dsb_msr_num; >>> u32 cmb_msr_num; >>> + u8 traceid; >>> }; >>> /* Enumerate members of various datasets */ >>> >>> --- >>> base-commit: b84a0ebe421ca56995ff78b66307667b62b3a900 >>> change-id: 20260316-add-traceid-show-for-tpdm-88d040651f00 >>> >>> Best regards, >> >> >

5 days, 3 hours

Re: [PATCH v2] coresight: tpdm: add traceid_show for checking traceid

by Suzuki K Poulose

On 16/03/2026 07:23, Jie Gan wrote: > Save the trace ID in drvdata during TPDM enablement and expose it > to userspace to support trace data parsing. > > The TPDM device’s trace ID corresponds to the trace ID allocated > to the connected TPDA device. > > Signed-off-by: Jie Gan <jie.gan(a)oss.qualcomm.com> > --- > Changes in V2: > 1. Use sysfs_emit instead of sprintf. > Link to V1 - https://lore.kernel.org/all/20260306-add-traceid-show-for-tpdm-v1-1-0658a8e… Why is this patch required even ? For each TPDM there is a single port in a single TPDA in the system where it can reach and that is fixed for a platform. Can we not get this from there ? Also, there is not TraceID technically for a TPDM, right ? It is all a property of the TPDA ? Suzuki > --- > drivers/hwtracing/coresight/coresight-tpdm.c | 31 +++++++++++++++++++++++++++- > drivers/hwtracing/coresight/coresight-tpdm.h | 2 ++ > 2 files changed, 32 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c > index da77bdaad0a4..774a63def817 100644 > --- a/drivers/hwtracing/coresight/coresight-tpdm.c > +++ b/drivers/hwtracing/coresight/coresight-tpdm.c > @@ -481,7 +481,7 @@ static void __tpdm_enable(struct tpdm_drvdata *drvdata) > > static int tpdm_enable(struct coresight_device *csdev, struct perf_event *event, > enum cs_mode mode, > - __maybe_unused struct coresight_path *path) > + struct coresight_path *path) > { > struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); > > @@ -497,6 +497,7 @@ static int tpdm_enable(struct coresight_device *csdev, struct perf_event *event, > } > > __tpdm_enable(drvdata); > + drvdata->traceid = path->trace_id; > drvdata->enable = true; > spin_unlock(&drvdata->spinlock); > > @@ -693,6 +694,26 @@ static struct attribute_group tpdm_attr_grp = { > .attrs = tpdm_attrs, > }; > > +static ssize_t traceid_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + unsigned long val; > + struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent); > + > + val = drvdata->traceid; > + return sysfs_emit(buf, "%#lx\n", val); > +} > +static DEVICE_ATTR_RO(traceid); > + > +static struct attribute *traceid_attrs[] = { > + &dev_attr_traceid.attr, > + NULL, > +}; > + > +static struct attribute_group traceid_attr_grp = { > + .attrs = traceid_attrs, > +}; > + > static ssize_t dsb_mode_show(struct device *dev, > struct device_attribute *attr, > char *buf) > @@ -1367,6 +1388,12 @@ static const struct attribute_group *tpdm_attr_grps[] = { > &tpdm_cmb_patt_grp, > &tpdm_cmb_msr_grp, > &tpdm_mcmb_attr_grp, > + &traceid_attr_grp, > + NULL, > +}; > + > +static const struct attribute_group *static_tpdm_attr_grps[] = { > + &traceid_attr_grp, > NULL, > }; > > @@ -1425,6 +1452,8 @@ static int tpdm_probe(struct device *dev, struct resource *res) > desc.access = CSDEV_ACCESS_IOMEM(base); > if (res) > desc.groups = tpdm_attr_grps; > + else > + desc.groups = static_tpdm_attr_grps; > drvdata->csdev = coresight_register(&desc);> if (IS_ERR(drvdata->csdev)) > return PTR_ERR(drvdata->csdev); > diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h > index 2867f3ab8186..befecbb896f4 100644 > --- a/drivers/hwtracing/coresight/coresight-tpdm.h > +++ b/drivers/hwtracing/coresight/coresight-tpdm.h > @@ -300,6 +300,7 @@ struct cmb_dataset { > * @cmb Specifics associated to TPDM CMB. > * @dsb_msr_num Number of MSR supported by DSB TPDM > * @cmb_msr_num Number of MSR supported by CMB TPDM > + * @traceid trace ID of the path. > */ > > struct tpdm_drvdata { > @@ -313,6 +314,7 @@ struct tpdm_drvdata { > struct cmb_dataset *cmb; > u32 dsb_msr_num; > u32 cmb_msr_num; > + u8 traceid; > }; > > /* Enumerate members of various datasets */ > > --- > base-commit: b84a0ebe421ca56995ff78b66307667b62b3a900 > change-id: 20260316-add-traceid-show-for-tpdm-88d040651f00 > > Best regards,

5 days, 5 hours

[PATCH] MAINTAINERS: coresight: Add Leo Yan as Reviewer

by Suzuki K Poulose

Leo has been an active contributor and reviewer for CoreSight subsystem for years. Add him as a Reviewer for CORESIGHT. Cc: Leo Yan <leo.yan(a)arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose(a)arm.com> --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) diff --git a/MAINTAINERS b/MAINTAINERS index 9c5491001908..eaf928246aaf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2710,6 +2710,7 @@ ARM/CORESIGHT FRAMEWORK AND DRIVERS M: Suzuki K Poulose <suzuki.poulose(a)arm.com> R: Mike Leach <mike.leach(a)arm.com> R: James Clark <james.clark(a)linaro.org> +R: Leo Yan <leo.yan(a)arm.com> L: coresight(a)lists.linaro.org (moderated for non-subscribers) L: linux-arm-kernel(a)lists.infradead.org (moderated for non-subscribers) S: Maintained -- 2.43.0

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