linux-kernel - Re: [PATCH 4.4 18/31] r8152: napi hangup fix after disconnect

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Date:   Sat, 25 Aug 2018 09:43:23 +0200
From:   Jiri Slaby <jslaby@...e.cz>
To:     Ben Hutchings <ben.hutchings@...ethink.co.uk>,
        linux-usb@...r.kernel.org, netdev@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>
Cc:     stable@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4.4 18/31] r8152: napi hangup fix after disconnect

On 08/24/2018, 06:38 PM, Ben Hutchings wrote:
> On Fri, 2018-07-20 at 14:13 +0200, Greg Kroah-Hartman wrote:
>> 4.4-stable review patch.  If anyone has any objections, please let me know.
>>
>> ------------------
>>
>> From: Jiri Slaby <jslaby@...e.cz>
>>
>> [ Upstream commit 0ee1f4734967af8321ecebaf9c74221ace34f2d5 ]
> [...]
>> --- a/drivers/net/usb/r8152.c
>> +++ b/drivers/net/usb/r8152.c
>> @@ -3139,7 +3139,8 @@ static int rtl8152_close(struct net_devi
>>  #ifdef CONFIG_PM_SLEEP
>>  	unregister_pm_notifier(&tp->pm_notifier);
>>  #endif
>> -	napi_disable(&tp->napi);
>> +	if (!test_bit(RTL8152_UNPLUG, &tp->flags))
>> +		napi_disable(&tp->napi);
>>  	clear_bit(WORK_ENABLE, &tp->flags);
>>  	usb_kill_urb(tp->intr_urb);
>>  	cancel_delayed_work_sync(&tp->schedule);
> 
> This flag appears to be set only if the USB device is actually
> disconnected.  In case the driver is unbound for some other reason
> (like the module is removed), the same problem will occur.

Could you elaborate? I thought this would happen:
module_exit -> usb_deregister -> usb_unbind_device -> rtl8152_disconnect
-> unregister_netdev -> rtl8152_close

Am I missing something?

thanks,
-- 
js
suse labs