From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AA46F1B6D1A for ; Sat, 3 Oct 2026 02:49:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790995759; cv=none; b=Ap3Qm3wFMKI+JrWGmdyNkBfAyTr9d62DedymszcLVKR15DtBhxQ/E/h6gw8fsBXlR8gtSKd7loOylgvxrpStoPFxgIiU94gbTHdfXkxkminzpjJAOeRQmB4Cy7HZV/HyWx1gSxr2vF2865VSsHOjZNjdnstXVuXe2KG+dfBXxD0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790995759; c=relaxed/simple; bh=I3vdyRRDlefC1oAiQIJXDmUOiroJlVmudGdEn1cielc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=giVmyiMGwkCaczIsR2/yCXmxOM5xJPFjCWd80U4SGI7FpUOWdoru13VksuYFxaldRYCzJKTc60j5PWnznoEexJgOWiSWpN0E42CR86UjAnnDIq+VRXCqp7VXYGozabIUqTeaLN+Fe1W66Ly+hrsRQFmrei+FFahCNXAYg5xKwAY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=M+hp/Kog; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="M+hp/Kog" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9488C2F; Fri, 2 Oct 2026 19:49:13 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C72063F763; Fri, 2 Oct 2026 19:49:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790995756; bh=I3vdyRRDlefC1oAiQIJXDmUOiroJlVmudGdEn1cielc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=M+hp/Kogl4r89iuULgtbNgsxVSeyZgDt8goPgeVRNoE3dRaV5kKbE7YpeGVfF1OoR xEKWuBh+ijfzy4XjDZZ/uDO+N6QnL+M+UxOAim6NpRsZQixCcovlDmX6EYGwv5s8q1 NV/9ak4la0JMisfPT06nH78LX2/XEZTgDo7n0Evk= Date: Sat, 3 Oct 2026 03:49:12 +0100 From: Yeoreum Yun To: Mike Leach , James Clark , Leo Yan , Greg Kroah-Hartman , Mathieu Poirier , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev Cc: Suzuki K Poulose , Alexander Shishkin , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , Yeoreum Yun Subject: Re: [PATCH v13 00/14] fix several inconsistencies with sysfs configuration in etmX Message-ID: References: <20261002-separate_etm_cfg_v2-v13-0-fe429d8d96fb@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261002-separate_etm_cfg_v2-v13-0-fe429d8d96fb@arm.com> Sashiko's review found one typo but others are not valid and I've commented for them. Therefore, I'll resend again with typo fix only keeping the version. Thanks! > 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: > > - curr_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. > > Patch History > ============= > from v12 to v13: > - add r-b tags > - Link to v12: https://lore.kernel.org/r/20260924-separate_etm_cfg_v2-v12-0-a2b41d2f7c2b@arm.com > > from v11 to v12: > - rename active_config to curr_config. > - rename config to sysfs_config. > - remove redundant config argument in etmX_args. > - add read-back and copy from curr_config to sysfs_config TRCSEQSTR > (seq_state). > - add r-b and t-b tags. > - Link to v11: https://lore.kernel.org/r/20260915-separate_etm_cfg_v2-v11-0-d2b258d51747@arm.com > > from v10 to v11: > - replace direct register read from etm3 sysfs with IPI. > - fix issue cntr_val and others field which required to be shown after > sysfs session disable. > - prohibit the write for some etm3 sysfs while sysfs session is > enabled. > - drop locktype change in etm3 > - Link to v10: https://lore.kernel.org/r/20260911-separate_etm_cfg_v2-v10-0-1b715d95927a@arm.com > > from v9 to v10: > - rebase to coresight/next > - https://lore.kernel.org/all/20260725113645.57519-1-yeoreum.yun@arm.com/ > > from v8 to v9: > - add feat_csdev_lock guard interface. > - set feat_csdev->drv_spinlock as NULL for etmv4_drvdata. > - https://lore.kernel.org/all/20260629090007.1718746-1-yeoreum.yun@arm.com/ > > 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 (14): > coresight: etm4x: read-back TRCSEQSTR at disabling and prohibit modifying seq_state while enabling. > coresight: etm4x: prohibit modifying cntr_val while session is enabled > coresight: etm3x: prohibit modifying cntr_val and reset while session is enabled > coresight: etm4x: fix inconsistencies with sysfs configuration > coresight: etm3x: fix inconsistencies with sysfs configuration > coresight: etm3x: remove redundant cpu online check on etm_enable_sysfs() > coresight: etm4x: introduce struct etm4_caps > coresight: etm4x: exclude ss_status from drvdata->config > coresight: etm4x: remove s_ex_level from config > coresight: etm4x: rename local config as curr_config referring drvdata->curr_config > coresight: etm4x: rename drvdata->config to sysfs_config > coresight: etm3x: introduce struct etm_caps > coresight: etm3x: rename local config as curr_config referring drvdata->curr_config > coresight: etm3x: rename drvdata->config to sysfs_config > > drivers/hwtracing/coresight/coresight-config.c | 18 +- > drivers/hwtracing/coresight/coresight-config.h | 22 + > drivers/hwtracing/coresight/coresight-etm.h | 48 +- > drivers/hwtracing/coresight/coresight-etm3x-core.c | 196 +++-- > .../hwtracing/coresight/coresight-etm3x-sysfs.c | 461 +++++----- > drivers/hwtracing/coresight/coresight-etm4x-cfg.c | 14 +- > drivers/hwtracing/coresight/coresight-etm4x-core.c | 567 ++++++------ > .../hwtracing/coresight/coresight-etm4x-sysfs.c | 961 +++++++++++---------- > drivers/hwtracing/coresight/coresight-etm4x.h | 199 +++-- > 9 files changed, 1340 insertions(+), 1146 deletions(-) > --- > base-commit: a3281934612608db9e1d24aaf913c846e913de89 > change-id: 20260911-separate_etm_cfg_v2-3518a168cbff > > Best regards, > -- > Sincerely, > Yeoreum Yun > -- Sincerely, Yeoreum Yun