Re: [PATCH] coresight: trbe: remove cpuhp instance node before remove cpuhp state

From: Suzuki Kuruppassery Poulose
Date: Thu Nov 24 2022 - 06:30:45 EST


On 22/11/2022 09:03, Yang Shen wrote:
cpuhp_state_add_instance() and cpuhp_state_remove_instance() should
be used in pairs. Or there will lead to the warn on
cpuhp_remove_multi_state() since the cpuhp_step list is not empty.

The following is the error log with 'rmmod coresight-trbe':
Error: Removing state 215 which has instances left.
Call trace:
__cpuhp_remove_state_cpuslocked+0x144/0x160
__cpuhp_remove_state+0xac/0x100
arm_trbe_device_remove+0x2c/0x60 [coresight_trbe]
platform_remove+0x34/0x70
device_remove+0x54/0x90
device_release_driver_internal+0x1e4/0x250
driver_detach+0x5c/0xb0
bus_remove_driver+0x64/0xc0
driver_unregister+0x3c/0x70
platform_driver_unregister+0x20/0x30
arm_trbe_exit+0x1c/0x658 [coresight_trbe]
__arm64_sys_delete_module+0x1ac/0x24c
invoke_syscall+0x50/0x120
el0_svc_common.constprop.0+0x58/0x1a0
do_el0_svc+0x38/0xd0
el0_svc+0x2c/0xc0
el0t_64_sync_handler+0x1ac/0x1b0
el0t_64_sync+0x19c/0x1a0
---[ end trace 0000000000000000 ]---

Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver")
Signed-off-by: Yang Shen <shenyang39@xxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-trbe.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 2b386bb848f8..1fc4fd79a1c6 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1434,6 +1434,7 @@ static int arm_trbe_probe_cpuhp(struct trbe_drvdata *drvdata)

static void arm_trbe_remove_cpuhp(struct trbe_drvdata *drvdata)
{
+ cpuhp_state_remove_instance(drvdata->trbe_online, &drvdata->hotplug_node);
cpuhp_remove_multi_state(drvdata->trbe_online);
}


Applied to coresight next.

https://git.kernel.org/coresight/c/5fefef85b0d3

Thanks
Suzuki

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2.24.0