Re: [PATCH v4 3/7] usb: gadget: define free_ep_req as universal function

[Robert Baldyga <r.baldyga@samsung.com>]

On 10/27/2015 10:18 AM, Felipe Ferreri Tonello wrote:
> Hi Robert,
> 
> On 27/10/15 06:53, Robert Baldyga wrote:
>> On 10/26/2015 05:55 PM, Felipe F. Tonello wrote:
>>> This function is shared between gadget functions, so this avoid unnecessary
>>> duplicated code and potentially avoid memory leaks.
>>>
>>> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
>>> ---
>>>  drivers/usb/gadget/function/f_midi.c       | 6 ------
>>>  drivers/usb/gadget/function/f_sourcesink.c | 6 ------
>>>  drivers/usb/gadget/function/g_zero.h       | 1 -
>>>  drivers/usb/gadget/u_f.c                   | 8 ++++++++
>>>  drivers/usb/gadget/u_f.h                   | 3 +--
>>>  5 files changed, 9 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
>>> index c19f154..4c01c8a 100644
>>> --- a/drivers/usb/gadget/function/f_midi.c
>>> +++ b/drivers/usb/gadget/function/f_midi.c
>>> @@ -202,12 +202,6 @@ static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep,
>>>  	return alloc_ep_req(ep, length, length);
>>>  }
>>>  
>>> -static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
>>> -{
>>> -	kfree(req->buf);
>>> -	usb_ep_free_request(ep, req);
>>> -}
>>> -
>>>  static const uint8_t f_midi_cin_length[] = {
>>>  	0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
>>>  };
>>> diff --git a/drivers/usb/gadget/function/f_sourcesink.c b/drivers/usb/gadget/function/f_sourcesink.c
>>> index 3a5ae99..eedea7f 100644
>>> --- a/drivers/usb/gadget/function/f_sourcesink.c
>>> +++ b/drivers/usb/gadget/function/f_sourcesink.c
>>> @@ -307,12 +307,6 @@ static inline struct usb_request *ss_alloc_ep_req(struct usb_ep *ep, int len)
>>>  	return alloc_ep_req(ep, len, buflen);
>>>  }
>>>  
>>> -void free_ep_req(struct usb_ep *ep, struct usb_request *req)
>>> -{
>>> -	kfree(req->buf);
>>> -	usb_ep_free_request(ep, req);
>>> -}
>>> -
>>>  static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
>>>  {
>>>  	int			value;
>>> diff --git a/drivers/usb/gadget/function/g_zero.h b/drivers/usb/gadget/function/g_zero.h
>>> index 15f1809..5ed90b4 100644
>>> --- a/drivers/usb/gadget/function/g_zero.h
>>> +++ b/drivers/usb/gadget/function/g_zero.h
>>> @@ -59,7 +59,6 @@ void lb_modexit(void);
>>>  int lb_modinit(void);
>>>  
>>>  /* common utilities */
>>> -void free_ep_req(struct usb_ep *ep, struct usb_request *req);
>>>  void disable_endpoints(struct usb_composite_dev *cdev,
>>>  		struct usb_ep *in, struct usb_ep *out,
>>>  		struct usb_ep *iso_in, struct usb_ep *iso_out);
>>> diff --git a/drivers/usb/gadget/u_f.c b/drivers/usb/gadget/u_f.c
>>> index c6276f0..f78bd1f 100644
>>> --- a/drivers/usb/gadget/u_f.c
>>> +++ b/drivers/usb/gadget/u_f.c
>>> @@ -14,6 +14,7 @@
>>>  #include <linux/usb/gadget.h>
>>>  #include "u_f.h"
>>>  
>>> +/* Requests allocated via alloc_ep_req() must be freed by free_ep_req(). */
>>>  struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len)
>>>  {
>>>  	struct usb_request      *req;
>>> @@ -30,3 +31,10 @@ struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len)
>>>  	return req;
>>>  }
>>>  EXPORT_SYMBOL_GPL(alloc_ep_req);
>>> +
>>> +void free_ep_req(struct usb_ep *ep, struct usb_request *req)
>>> +{
>>> +	kfree(req->buf);
>>> +	usb_ep_free_request(ep, req);
>>> +}
>>> +EXPORT_SYMBOL_GPL(free_ep_req);
>>> diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
>>> index 1d5f0eb..2a1a6fb 100644
>>> --- a/drivers/usb/gadget/u_f.h
>>> +++ b/drivers/usb/gadget/u_f.h
>>> @@ -46,7 +46,6 @@ struct usb_ep;
>>>  struct usb_request;
>>>  
>>>  struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len);
>>> +void free_ep_req(struct usb_ep *ep, struct usb_request *req);
>>>  
>>>  #endif /* __U_F_H__ */
>>> -
>>> -
>>>
>>
>> Isn't it simple enough to be static inline?
> 
> inline yes. And the compiler will do it automatically. But I can add it
> for clarity.

No, compiler will never make function inline when you export its symbol.
To make it inline you should place it in header.

> 
> Make it static it doesn't make sense. This function is exported in the
> kernel.
> 

Best regards,
Robert