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Message-ID: <a7eb525a-3c96-7477-d5eb-7f93a1b49cb8@arm.com>
Date:   Thu, 24 Nov 2022 11:30:36 +0000
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Subject: Re: [PATCH] coresight: trbe: remove cpuhp instance node before remove
 cpuhp state
Content-Language: en-US
To:     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>
From:   Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>
In-Reply-To: <20221122090355.23533-1-shenyang39@huawei.com>
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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>
> ---
>   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

> --
> 2.24.0
>