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Subject: Re: [PATCH] usb: gadget: udc: core: Fix error case while binding
 pending gadget drivers
To:     Alan Stern <stern@rowland.harvard.edu>
CC:     <balbi@kernel.org>, <gregkh@linuxfoundation.org>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <Pine.LNX.4.44L0.1908211027430.1816-100000@iolanthe.rowland.org>
From:   Roger Quadros <rogerq@ti.com>
Message-ID: <9eba7e43-5692-b9c7-b30c-39a60e3239a6@ti.com>
Date:   Thu, 22 Aug 2019 16:37:39 +0300
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On 21/08/2019 17:30, Alan Stern wrote:
> On Wed, 21 Aug 2019, Roger Quadros wrote:
> 
>> If binding a pending gadget driver fails we should not
>> remove it from the pending driver list, otherwise it
>> will cause a segmentation fault later when the gadget driver is
>> unloaded.
> 
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>>  drivers/usb/gadget/udc/core.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
>> index 7cf34beb50df..c272c8014772 100644
>> --- a/drivers/usb/gadget/udc/core.c
>> +++ b/drivers/usb/gadget/udc/core.c
>> @@ -1142,7 +1142,7 @@ static int check_pending_gadget_drivers(struct usb_udc *udc)
>>  		if (!driver->udc_name || strcmp(driver->udc_name,
>>  						dev_name(&udc->dev)) == 0) {
>>  			ret = udc_bind_to_driver(udc, driver);
>> -			if (ret != -EPROBE_DEFER)
>> +			if (!ret)
>>  				list_del(&driver->pending);
>>  			break;
>>  		}
> 
> This is kind of a policy question.  If binding a pending gadget driver 
> fails, should the driver remain pending?
> 
> Depending on the answer to this question, you might want to change the 
> list_del to list_del_init.  That should fix the segmentation fault 
> just as well.

OK. I'll send a revised patch to retain existing policy.

cheers,
-roger
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