Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Subject: Re: [PATCH -next] w1: fix WARNING after calling w1_process()
From:   Yang Yingliang <yangyingliang@huawei.com>
To:     <linux-kernel@vger.kernel.org>
CC:     <david@fries.net>, <gregkh@linuxfoundation.org>
References: <20221205100808.3595615-1-yangyingliang@huawei.com>
Message-ID: <5f982a08-c3aa-57eb-b426-d809bf45585d@huawei.com>
Date:   Mon, 5 Dec 2022 18:16:35 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101
 Thunderbird/68.7.0
MIME-Version: 1.0
In-Reply-To: <20221205100808.3595615-1-yangyingliang@huawei.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Precedence: bulk

Please ignore this patch, it's not for next.

On 2022/12/5 18:08, Yang Yingliang wrote:
> I got the following WARNING message while removing driver(ds2482):
>
> ------------[ cut here ]------------
> do not call blocking ops when !TASK_RUNNING; state=1 set at [<000000002d50bfb6>] w1_process+0x9e/0x1d0 [wire]
> WARNING: CPU: 0 PID: 262 at kernel/sched/core.c:9817 __might_sleep+0x98/0xa0
> CPU: 0 PID: 262 Comm: w1_bus_master1 Tainted: G                 N 6.1.0-rc3+ #307
> RIP: 0010:__might_sleep+0x98/0xa0
> Call Trace:
>   exit_signals+0x6c/0x550
>   do_exit+0x2b4/0x17e0
>   kthread_exit+0x52/0x60
>   kthread+0x16d/0x1e0
>   ret_from_fork+0x1f/0x30
>
> The state of task is set to TASK_INTERRUPTIBLE in loop in w1_process(),
> set it to TASK_RUNNING when it breaks out of the loop to avoid the
> warning.
>
> Fixes: 3c52e4e62789 ("W1: w1_process, block or sleep")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>   drivers/w1/w1.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
> index 8b35fae4cd61..4a2ddf730a3a 100644
> --- a/drivers/w1/w1.c
> +++ b/drivers/w1/w1.c
> @@ -1195,8 +1195,10 @@ int w1_process(void *data)
>   		 */
>   		mutex_unlock(&dev->list_mutex);
>   
> -		if (kthread_should_stop())
> +		if (kthread_should_stop()) {
> +			__set_current_state(TASK_RUNNING);
>   			break;
> +		}
>   
>   		/* Only sleep when the search is active. */
>   		if (dev->search_count) {