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Subject: Re: [PATCH v2 1/2] usb: gadget: udc: core: Revise comments for
 usb_ep_disable()
To:     Alan Stern <stern@rowland.harvard.edu>
CC:     <balbi@kernel.org>, <gregkh@linuxfoundation.org>,
        <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>,
        <jackp@codeaurora.org>
References: <1635303025-772-1-git-send-email-quic_wcheng@quicinc.com>
 <1635303025-772-2-git-send-email-quic_wcheng@quicinc.com>
 <20211027142422.GA1319606@rowland.harvard.edu>
From:   Wesley Cheng <quic_wcheng@quicinc.com>
Message-ID: <2c39336e-289e-b0c7-66a3-7aa844a0b252@quicinc.com>
Date:   Wed, 27 Oct 2021 12:58:02 -0700
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Hi Alan,

On 10/27/2021 7:24 AM, Alan Stern wrote:
> On Tue, Oct 26, 2021 at 07:50:24PM -0700, Wesley Cheng wrote:
>> The usb_ep_disable() routine is being widely used directly in the
>> disconnect callback path by function drivers.  Hence, the statement
>> about it being able to only run in process context may not be true.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>  drivers/usb/gadget/udc/core.c | 2 --
>>  1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
>> index d626511..e1f90d8 100644
>> --- a/drivers/usb/gadget/udc/core.c
>> +++ b/drivers/usb/gadget/udc/core.c
>> @@ -136,8 +136,6 @@ EXPORT_SYMBOL_GPL(usb_ep_enable);
>>   * gadget drivers must call usb_ep_enable() again before queueing
>>   * requests to the endpoint.
>>   *
>> - * This routine must be called in process context.
>> - *
>>   * returns zero, or a negative error code.
>>   */
>>  int usb_ep_disable(struct usb_ep *ep)
> 
> You should also change the kerneldoc for usb_ep_enable.  Neither routine 
> needs to be called in process context.
> 
> In fact, it might be good to change both comments to:
> 
>  * This routine may be called in an atomic (interrupt) context.
> 
> just to be totally explicit.
> 
Ah, missed the ep enable case as well, thanks for the catch.  Sounds
good, I'll add that statement.

Thanks
Wesley Cheng