From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: gregkh@linuxfoundation.org
Cc: coresight@lists.linaro.org, mike.leach@linaro.org,
mathieu.poirier@linaro.org, linux-arm-kernel@lists.infradead.org,
James Clark <james.clark@arm.com>,
Aishwarya TCV <Aishwarya.TCV@arm.com>,
Cristian Marussi <Cristian.Marussi@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH] coresight: cti: Fix hang in cti_disable_hw()
Date: Tue, 25 Oct 2022 14:10:32 +0100 [thread overview]
Message-ID: <20221025131032.1149459-1-suzuki.poulose@arm.com> (raw)
From: James Clark <james.clark@arm.com>
cti_enable_hw() and cti_disable_hw() are called from an atomic context
so shouldn't use runtime PM because it can result in a sleep when
communicating with firmware.
Since commit 3c6656337852 ("Revert "firmware: arm_scmi: Add clock
management to the SCMI power domain""), this causes a hang on Juno when
running the Perf Coresight tests or running this command:
perf record -e cs_etm//u -- ls
This was also missed until the revert commit because pm_runtime_put()
was called with the wrong device until commit 692c9a499b28 ("coresight:
cti: Correct the parameter for pm_runtime_put")
With lock and scheduler debugging enabled the following is output:
coresight cti_sys0: cti_enable_hw -- dev:cti_sys0 parent: 20020000.cti
BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1151
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 330, name: perf-exec
preempt_count: 2, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last enabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 3 PID: 330 Comm: perf-exec Not tainted 6.0.0-00053-g042116d99298 #7
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Sep 13 2022
Call trace:
dump_backtrace+0x134/0x140
show_stack+0x20/0x58
dump_stack_lvl+0x8c/0xb8
dump_stack+0x18/0x34
__might_resched+0x180/0x228
__might_sleep+0x50/0x88
__pm_runtime_resume+0xac/0xb0
cti_enable+0x44/0x120
coresight_control_assoc_ectdev+0xc0/0x150
coresight_enable_path+0xb4/0x288
etm_event_start+0x138/0x170
etm_event_add+0x48/0x70
event_sched_in.isra.122+0xb4/0x280
merge_sched_in+0x1fc/0x3d0
visit_groups_merge.constprop.137+0x16c/0x4b0
ctx_sched_in+0x114/0x1f0
perf_event_sched_in+0x60/0x90
ctx_resched+0x68/0xb0
perf_event_exec+0x138/0x508
begin_new_exec+0x52c/0xd40
load_elf_binary+0x6b8/0x17d0
bprm_execve+0x360/0x7f8
do_execveat_common.isra.47+0x218/0x238
__arm64_sys_execve+0x48/0x60
invoke_syscall+0x4c/0x110
el0_svc_common.constprop.4+0xfc/0x120
do_el0_svc+0x34/0xc0
el0_svc+0x40/0x98
el0t_64_sync_handler+0x98/0xc0
el0t_64_sync+0x170/0x174
Fix the issue by removing the runtime PM calls completely. They are not
needed here because it must have already been done when building the
path for a trace.
Fixes: 835d722ba10a ("coresight: cti: Initial CoreSight CTI Driver")
Reported-by: Aishwarya TCV <Aishwarya.TCV@arm.com>
Reported-by: Cristian Marussi <Cristian.Marussi@arm.com>
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
[ Fix build warnings ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Greg,
Please could you apply this patch to your tree.
Thanks
Suzuki
Changes since previous posting:
- Fix build warnings with 'unused variable'
---
drivers/hwtracing/coresight/coresight-cti-core.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 1be92342b5b9..c6e8c6542f24 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -90,11 +90,9 @@ void cti_write_all_hw_regs(struct cti_drvdata *drvdata)
static int cti_enable_hw(struct cti_drvdata *drvdata)
{
struct cti_config *config = &drvdata->config;
- struct device *dev = &drvdata->csdev->dev;
unsigned long flags;
int rc = 0;
- pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
/* no need to do anything if enabled or unpowered*/
@@ -119,7 +117,6 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
/* cannot enable due to error */
cti_err_not_enabled:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- pm_runtime_put(dev->parent);
return rc;
}
@@ -153,7 +150,6 @@ static void cti_cpuhp_enable_hw(struct cti_drvdata *drvdata)
static int cti_disable_hw(struct cti_drvdata *drvdata)
{
struct cti_config *config = &drvdata->config;
- struct device *dev = &drvdata->csdev->dev;
struct coresight_device *csdev = drvdata->csdev;
spin_lock(&drvdata->spinlock);
@@ -175,7 +171,6 @@ static int cti_disable_hw(struct cti_drvdata *drvdata)
coresight_disclaim_device_unlocked(csdev);
CS_LOCK(drvdata->base);
spin_unlock(&drvdata->spinlock);
- pm_runtime_put(dev->parent);
return 0;
/* not disabled this call */
--
2.37.3
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next reply other threads:[~2022-10-25 16:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-25 13:10 Suzuki K Poulose [this message]
2022-10-26 8:52 ` [PATCH] coresight: cti: Fix hang in cti_disable_hw() Anshuman Khandual
-- strict thread matches above, loose matches on Subject: below --
2022-10-05 13:14 James Clark
2022-10-05 13:14 ` James Clark
2022-10-05 13:24 ` James Clark
2022-10-05 13:24 ` James Clark
2022-10-19 13:53 ` Mike Leach
2022-10-19 13:53 ` Mike Leach
2022-10-19 14:51 ` Suzuki K Poulose
2022-10-19 14:51 ` Suzuki K Poulose
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