On Tue, 18 Aug 2020 at 12:11, Tingwei Zhang tingwei@codeaurora.org wrote:
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") Signed-off-by: Tingwei Zhang tingwei@codeaurora.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 3ccc703dc940..d6fea6efec71 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;}
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Reviewed-by: Mike Leach mike.leach@linaro.org