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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: fxjFGU31QZD2dJ66PYH25o1mDOfaJcKXwfuGtQmA0XoSlaxg94//9OkAzVNSHM4iB9/FTrKGShzIBPw6J/YyIiTirXRh1VN3vLkDnH1RKrbDrm8eW9K8uXb8eCHhm6BRukw9b2RHEHpnTMK+u+cC9HCJP/OXPOzTyW35a5wY16OfFPjDRuhJDTBbeIH+4bz9AzX2Oi+kERxnVv7Th/PlQiSZ6iAE/yFjkzWGkyLtsG4+4gGAYAK3Ha16sMJ2Ck0j/raP134fwVZZ3da71hr/y9E3xJn195rTo6oE/q75RQurcD+gLv9WGluZCDUthHZP+2y+VJ7j0JmjQOQu48PmK56VC0poHfU7mjdizkbYmWib3JF5jOiCsabVSXsfNgnjROpZgI71gEOeO28gzmMd9NZ9LLBCMttB+EJg/15ztqxnACl55HH+6OztS+RPsrsI X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Sep 2026 10:40:40.8141 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 98b43498-dfcb-43e8-6b33-08df1e161b87 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: MI3PEPF00008550.eurprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MMZPR08MB615799 Reviewed-by: Mike Leach On 9/24/26 18:33, Yeoreum Yun wrote: > TRCSEQSTR can be changed by the ETM while a session is active. Its value > therefore needs to be preserved when a sysfs session is disabled so that > users can read the current sequence state after the session ends. > > This means that any changes made to TRCSEQSTR while the sysfs-session is active > would be lost when the session is disabled. > > Copy the TRCSEQSTR value when disabling a sysfs session, and prohibit > modifying seq_state while the session is active. > > Suggested-by: Mike Leach > Signed-off-by: Yeoreum Yun > --- > drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 ++++ > drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 2 ++ > 2 files changed, 6 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 2247ad55d444..9ca03a5913a3 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -1073,6 +1073,10 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata) > etm4x_relaxed_read32(csa, TRCCNTVRn(i)); > } > > + /* read back the sequence state */ > + if (drvdata->nrseqstate) > + config->seq_state = etm4x_relaxed_read32(csa, TRCSEQSTR); > + > coresight_disclaim_device_unlocked(csdev); > etm4_cs_lock(drvdata, csa); > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > index cc6cdd3ae29d..db3cf4ad6806 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > @@ -1437,6 +1437,8 @@ static ssize_t seq_state_store(struct device *dev, > return -EINVAL; > if (val >= drvdata->nrseqstate) > return -EINVAL; > + if (IS_ERR_OR_NULL(drvdata) || coresight_get_mode(drvdata->csdev)) > + return -EBUSY; > > config->seq_state = val; > return size; >