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* [PATCH v8 00/13] fix several inconsistencies with sysfs configuration in etmX
@ 2026-06-29  8:59 Yeoreum Yun
  2026-06-29  8:59 ` [PATCH v8 01/13] coresight: etm4x: fix wrong check of etm4x_sspcicrn_present() Yeoreum Yun
                   ` (12 more replies)
  0 siblings, 13 replies; 18+ messages in thread
From: Yeoreum Yun @ 2026-06-29  8:59 UTC (permalink / raw)
  To: coresight, linux-arm-kernel, linux-kernel
  Cc: suzuki.poulose, mike.leach, james.clark, alexander.shishkin,
	leo.yan, jie.gan, Yeoreum Yun

The current ETMx configuration via sysfs can lead to the following
inconsistencies:

  - If a configuration is modified via sysfs while a perf session is
    active, the running configuration may differ between before
    a sched-out and after a subsequent sched-in.

  - If a perf session and sysfs session tries to enable concurrently,
    configuration from configfs could be corrupted (etm4).

  - There is chance to corrupt drvdata->config if perf session tries
    to enabled among handling cscfg_csdev_disable_active_config()
    in etm4_disable_sysfs() (etm4).

To resolve these inconsistencies, the configuration should be separated into:

  - active_config, which is applied configuration for the current session
  - config, which stores the settings configured via sysfs.

and apply configuration from configfs after taking a mode.

Also, This patch set includes some small fixes:
  - missing trace id release in etm4x.
  - underflow issue for nrseqstate.
  - wrong check in etm4x_sspcicrn_present().
  - missing call of cscfg_csdev_disable_active_config()

This patch based on coresight tree's next

Patch History
=============
from v7 to v8:
  - accept @Leo Yan' suggestion to handle error.
  - small minor fixes following @Suzuki' suggestion.
  - https://lore.kernel.org/all/20260519154812.254884-1-yeoreum.yun@arm.com/

from v6 to v7:
  - rebase on coresight/next
  - add ETM_MAX_SEQ_TRANSITIONS define
  - remove redundant patch relavent cpu-hotplug as coresight-pm patch
    merged.
  - https://lore.kernel.org/all/20260422132203.977549-1-yeoreum.yun@arm.com/

from v5 to v6:
  - fix missing of calling cscfg_csdev_disable_active_config()
  - add rb & fixes tags.
  - add ss_status field in etm4x_drvdata to expose STATUS and PENDING bits.
  - https://lore.kernel.org/all/20260415165528.3369607-1-yeoreum.yun@arm.com/

from v4 to v5:
  - add rb-tag.
  - fix underflow issue for nrseqstate.
  - fix wrong check in etm4_sspcicrn_present().
  - remove redundant fields on etmv4_save_state.
  - rename caps->ss_status to ss_cmp.
  - fix wrong location of etm4_release_trace_id.
  - https://lore.kernel.org/all/20260413142003.3549310-1-yeoreum.yun@arm.com/

from v3 to v4:
  - change etm_drvdata->spinlock type to raw_spin_lock_t
  - remove redundant call etmX_enable_hw() with starting_cpu() callsback.
  - fix missing trace id release.
  - add missing docs.
  - https://lore.kernel.org/all/20260412175506.412301-1-yeoreum.yun@arm.com/

from v2 to v3:
  - fix build error for etm3x.
  - fix checkpatch warning.
  - https://lore.kernel.org/all/20260410074310.2693385-1-yeoreum.yun@arm.com/

from v1 to v2
  - rebased to v7.0-rc7.
  - introduce etmX_caps structure to save etmX's capabilities.
  - remove ss_status from etmv4_config.
  - modify active_config after taking a mode (perf/sysfs).
  - https://lore.kernel.org/all/20260317181705.2456271-1-yeoreum.yun@arm.com/


Yeoreum Yun (13):
  coresight: etm4x: fix wrong check of etm4x_sspcicrn_present()
  coresight: etm4x: fix underflow for usage of (nrseqstate - 1)
  coresight: etm4x: introduce struct etm4_caps
  coresight: etm4x: exclude ss_status from drvdata->config
  coresight: etm4x: remove s_ex_level from config
  coresight: etm4x: remove redundant fields in etmv4_save_state
  coresight: etm4x: fix leaked trace id
  coresight: etm4x: fix inconsistencies with sysfs configuration
  coresight: etm4x: missing cscfg_csdev_disable_active_config() in perf
    enable
  coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t
  coresight: etm3x: introduce struct etm_caps
  coresight: etm3x: fix inconsistencies with sysfs configuration
  coresight: etm3x: remove redundant cpu online check on
    etm_enable_sysfs()

 drivers/hwtracing/coresight/coresight-etm.h   |  46 +-
 .../coresight/coresight-etm3x-core.c          |  96 ++--
 .../coresight/coresight-etm3x-sysfs.c         | 159 +++---
 .../hwtracing/coresight/coresight-etm4x-cfg.c |   5 +-
 .../coresight/coresight-etm4x-core.c          | 454 ++++++++++--------
 .../coresight/coresight-etm4x-sysfs.c         | 204 ++++----
 drivers/hwtracing/coresight/coresight-etm4x.h | 202 ++++----
 7 files changed, 639 insertions(+), 527 deletions(-)

-- 
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^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2026-07-06 18:21 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-06-29  8:59 [PATCH v8 00/13] fix several inconsistencies with sysfs configuration in etmX Yeoreum Yun
2026-06-29  8:59 ` [PATCH v8 01/13] coresight: etm4x: fix wrong check of etm4x_sspcicrn_present() Yeoreum Yun
2026-06-29  8:59 ` [PATCH v8 02/13] coresight: etm4x: fix underflow for usage of (nrseqstate - 1) Yeoreum Yun
2026-06-29  8:59 ` [PATCH v8 03/13] coresight: etm4x: introduce struct etm4_caps Yeoreum Yun
2026-06-29  8:59 ` [PATCH v8 04/13] coresight: etm4x: exclude ss_status from drvdata->config Yeoreum Yun
2026-06-29  8:59 ` [PATCH v8 05/13] coresight: etm4x: remove s_ex_level from config Yeoreum Yun
2026-06-29  8:59 ` [PATCH v8 06/13] coresight: etm4x: remove redundant fields in etmv4_save_state Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 07/13] coresight: etm4x: fix leaked trace id Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 08/13] coresight: etm4x: fix inconsistencies with sysfs configuration Yeoreum Yun
2026-07-06 17:21   ` Leo Yan
2026-07-06 18:16     ` Yeoreum Yun
2026-07-06 17:39   ` Leo Yan
2026-07-06 18:20     ` Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 09/13] coresight: etm4x: missing cscfg_csdev_disable_active_config() in perf enable Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 10/13] coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 11/13] coresight: etm3x: introduce struct etm_caps Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 12/13] coresight: etm3x: fix inconsistencies with sysfs configuration Yeoreum Yun
2026-06-29  9:00 ` [PATCH v8 13/13] coresight: etm3x: remove redundant cpu online check on etm_enable_sysfs() Yeoreum Yun

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