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Message-ID: <84b33e86-be89-4242-1cff-5c60c037c603@arm.com>
Date:   Thu, 24 Nov 2022 12:29:52 +0000
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Subject: Re: [PATCH] coresight: trbe: remove cpuhp instance node before remove
 cpuhp state
Content-Language: en-US
To:     Anshuman Khandual <anshuman.khandual@arm.com>,
        Yang Shen <shenyang39@huawei.com>, mathieu.poirier@linaro.org,
        mike.leach@linaro.org, leo.yan@linaro.org
Cc:     linux-kernel@vger.kernel.org, coresight@lists.linaro.org
References: <20221122090355.23533-1-shenyang39@huawei.com>
 <a7eb525a-3c96-7477-d5eb-7f93a1b49cb8@arm.com>
 <db88206c-2de3-3309-7671-55fdb2268a81@arm.com>
From:   Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>
In-Reply-To: <db88206c-2de3-3309-7671-55fdb2268a81@arm.com>
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On 24/11/2022 12:22, Anshuman Khandual wrote:
> 
> 
> On 11/24/22 17:00, Suzuki Kuruppassery Poulose wrote:
>> 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@huawei.com>
> 
> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> 
>>> ---
>>>    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
> 
> Hi Suzuki,
> 
> Could you please add the above tag for the patch. Thank you.

Sorry, its too late. It is already in the upstream tree.

Suzuki