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([2a02:2455:31d:5400:d829:a1a8:dbfd:4976]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47ee55c5b1asm16020615e9.5.2026.01.14.00.26.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 14 Jan 2026 00:26:55 -0800 (PST) Message-ID: <8bed5082-0aef-4dee-8239-c3e8aba50f9f@suse.com> Date: Wed, 14 Jan 2026 09:26:54 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [usb?] INFO: task hung in i2c_tiny_usb_disconnect To: weipeng Cc: anna-maria@linutronix.de, frederic@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de References: <20260114081100.830758-1-coderlogicwei@gmail.com> Content-Language: en-US From: Oliver Neukum In-Reply-To: <20260114081100.830758-1-coderlogicwei@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 14.01.26 09:11, weipeng wrote: > I got it. It can be solved by using wait_for_completion in the module exit > function to wait for all the i2c_tiny_usb_release() to be done. At that point the module unload would potentially take forever, because you cannot control how long it takes to complete. > The i2c_del_adapter() will wait for all the users to put the reference of the adapter. That seems reasonable. > It is not a good idea. We can't control the users. So the i2c_del_adapter() can wait > for any time. Who exactly takes references? I think at this point you have a design issue with the i2c layer and seems proper to include the linux-i2c list. Regards Oliver