[PATCH 5.8 230/633] coresight: cti: disclaim device only when its claimed

Greg Kroah-Hartman
2020-10-27T17:20:48Z

From: Tingwei Zhang <tingwei@codeaurora.org>

[ Upstream commit 0dee28268ddbe53a981d4d87faf5dc0f1700e698 ]

Coresight_claim_device() is called in cti_starting_cpu() only
when CTI is enabled while coresight_disclaim_device() is called
uncontionally in cti_dying_cpu(). This triggered below WARNING.
Only call disclaim device when CTI device is enabled to fix it.

[ 75.989643] WARNING: CPU: 1 PID: 14 at
kernel/drivers/hwtracing/coresight/coresight.c:209
coresight_disclaim_device_unlocked+0x10/0x24
[ 75.989697] CPU: 1 PID: 14 Comm: migration/1 Not tainted
5.9.0-rc1-gff1304be0a05-dirty #21
[ 75.989709] Hardware name: Thundercomm Dragonboard 845c (DT)
[ 75.989737] pstate: 80c00085 (Nzcv daIf +PAN +UAO BTYPE=--)
[ 75.989758] pc : coresight_disclaim_device_unlocked+0x10/0x24
[ 75.989775] lr : coresight_disclaim_device+0x24/0x38
[ 75.989783] sp : ffff800011cd3c90
.
[ 75.990018] Call trace:
[ 75.990041] coresight_disclaim_device_unlocked+0x10/0x24
[ 75.990066] cti_dying_cpu+0x34/0x4c
[ 75.990101] cpuhp_invoke_callback+0x84/0x1e0
[ 75.990121] take_cpu_down+0x90/0xe0
[ 75.990154] multi_cpu_stop+0x134/0x160
[ 75.990171] cpu_stopper_thread+0xb0/0x13c
[ 75.990196] smpboot_thread_fn+0x1c4/0x270
[ 75.990222] kthread+0x128/0x154
[ 75.990251] ret_from_fork+0x10/0x18

Fixes: e9b880581d55 ("coresight: cti: Add CPU Hotplug handling to CTI driver")
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200916191737.4001561-6-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwtracing/coresight/coresight-cti.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
index 3ccc703dc9409..d6fea6efec71f 100644
--- a/drivers/hwtracing/coresight/coresight-cti.c
+++ b/drivers/hwtracing/coresight/coresight-cti.c
@@ -742,7 +742,8 @@ static int cti_dying_cpu(unsigned int cpu)

spin_lock(&drvdata->spinlock);
drvdata->config.hw_powered = false;
- coresight_disclaim_device(drvdata->base);
+ if (drvdata->config.hw_enabled)
+ coresight_disclaim_device(drvdata->base);
spin_unlock(&drvdata->spinlock);
return 0;
}
--
2.25.1