On 11/04/2015 11:15 AM, Felipe Ferreri Tonello wrote:
> Hi Robert,
> 
> On 03/11/15 12:53, Robert Baldyga wrote:
>> USB requests in Loopback function are allocated in loopback_get_alt()
>> function, so we prefer to free them rather in loopback_disable() than
>> in loopback_complete() when request is completed with error. It provides
>> better symetry in resource management and improves code readability.
> 
> Are we doing this for all functions? Because I see that several
> functions does the same thing, they free IN/OUT ep requests on
> complete() instead of disable().
> 
> I also prefer this, but then we need to refactor most function code.
> 

I'm planning to convert all USB Functions to new API anyway, which
involves lots of refactoring, so it can be done en passant. Moreover
patch 14 of this series introduces clear_alt() operation, which is more
suitable place to free resources allocated in set_alt().

Thanks,
Robert Baldyga

>>
>> Signed-off-by: Robert Baldyga <r.bald...@samsung.com>
>> ---
>>  drivers/usb/gadget/function/f_loopback.c | 58 
>> +++++++++++++-------------------
>>  1 file changed, 23 insertions(+), 35 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/function/f_loopback.c 
>> b/drivers/usb/gadget/function/f_loopback.c
>> index 6b2102b..41464ae 100644
>> --- a/drivers/usb/gadget/function/f_loopback.c
>> +++ b/drivers/usb/gadget/function/f_loopback.c
>> @@ -35,6 +35,9 @@ struct f_loopback {
>>      struct usb_ep           *in_ep;
>>      struct usb_ep           *out_ep;
>>  
>> +    struct usb_request      *in_req;
>> +    struct usb_request      *out_req;
>> +
>>      unsigned                qlen;
>>      unsigned                buflen;
>>  };
>> @@ -249,30 +252,25 @@ static void loopback_complete(struct usb_ep *ep, 
>> struct usb_request *req)
>>                       * We received some data from the host so let's
>>                       * queue it so host can read the from our in ep
>>                       */
>> -                    struct usb_request *in_req = req->context;
>> -
>> -                    in_req->zero = (req->actual < req->length);
>> -                    in_req->length = req->actual;
>> +                    loop->in_req->zero = (req->actual < req->length);
>> +                    loop->in_req->length = req->actual;
>> +                    req = loop->in_req;
>>                      ep = loop->in_ep;
>> -                    req = in_req;
>>              } else {
>>                      /*
>>                       * We have just looped back a bunch of data
>>                       * to host. Now let's wait for some more data.
>>                       */
>> -                    req = req->context;
>> +                    req = loop->out_req;
>>                      ep = loop->out_ep;
>>              }
>>  
>>              /* queue the buffer back to host or for next bunch of data */
>>              status = usb_ep_queue(ep, req, GFP_ATOMIC);
>> -            if (status == 0) {
>> -                    return;
>> -            } else {
>> +            if (status < 0)
>>                      ERROR(cdev, "Unable to loop back buffer to %s: %d\n",
>>                            ep->name, status);
>> -                    goto free_req;
>> -            }
>> +            break;
>>  
>>              /* "should never get here" */
>>      default:
>> @@ -280,20 +278,10 @@ static void loopback_complete(struct usb_ep *ep, 
>> struct usb_request *req)
>>                              status, req->actual, req->length);
>>              /* FALLTHROUGH */
>>  
>> -    /* NOTE:  since this driver doesn't maintain an explicit record
>> -     * of requests it submitted (just maintains qlen count), we
>> -     * rely on the hardware driver to clean up on disconnect or
>> -     * endpoint disable.
>> -     */
>>      case -ECONNABORTED:             /* hardware forced ep reset */
>>      case -ECONNRESET:               /* request dequeued */
>>      case -ESHUTDOWN:                /* disconnect from host */
>> -free_req:
>> -            usb_ep_free_request(ep == loop->in_ep ?
>> -                                loop->out_ep : loop->in_ep,
>> -                                req->context);
>> -            free_ep_req(ep, req);
>> -            return;
>> +            break;
>>      }
>>  }
>>  
>> @@ -316,7 +304,6 @@ static inline struct usb_request *lb_alloc_ep_req(struct 
>> usb_ep *ep, int len)
>>  static int alloc_requests(struct usb_composite_dev *cdev,
>>                        struct f_loopback *loop)
>>  {
>> -    struct usb_request *in_req, *out_req;
>>      int i;
>>      int result = 0;
>>  
>> @@ -329,23 +316,21 @@ static int alloc_requests(struct usb_composite_dev 
>> *cdev,
>>      for (i = 0; i < loop->qlen && result == 0; i++) {
>>              result = -ENOMEM;
>>  
>> -            in_req = usb_ep_alloc_request(loop->in_ep, GFP_KERNEL);
>> -            if (!in_req)
>> +            loop->in_req = usb_ep_alloc_request(loop->in_ep, GFP_KERNEL);
>> +            if (!loop->in_req)
>>                      goto fail;
>>  
>> -            out_req = lb_alloc_ep_req(loop->out_ep, 0);
>> -            if (!out_req)
>> +            loop->out_req = lb_alloc_ep_req(loop->out_ep, 0);
>> +            if (!loop->out_req)
>>                      goto fail_in;
>>  
>> -            in_req->complete = loopback_complete;
>> -            out_req->complete = loopback_complete;
>> +            loop->in_req->complete = loopback_complete;
>> +            loop->out_req->complete = loopback_complete;
>>  
>> -            in_req->buf = out_req->buf;
>> +            loop->in_req->buf = loop->out_req->buf;
>>              /* length will be set in complete routine */
>> -            in_req->context = out_req;
>> -            out_req->context = in_req;
>>  
>> -            result = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
>> +            result = usb_ep_queue(loop->out_ep, loop->out_req, GFP_ATOMIC);
>>              if (result) {
>>                      ERROR(cdev, "%s queue req --> %d\n",
>>                                      loop->out_ep->name, result);
>> @@ -356,9 +341,9 @@ static int alloc_requests(struct usb_composite_dev *cdev,
>>      return 0;
>>  
>>  fail_out:
>> -    free_ep_req(loop->out_ep, out_req);
>> +    free_ep_req(loop->out_ep, loop->out_req);
>>  fail_in:
>> -    usb_ep_free_request(loop->in_ep, in_req);
>> +    usb_ep_free_request(loop->in_ep, loop->in_req);
>>  fail:
>>      return result;
>>  }
>> @@ -426,6 +411,9 @@ static void loopback_disable(struct usb_function *f)
>>      struct f_loopback       *loop = func_to_loop(f);
>>  
>>      disable_loopback(loop);
>> +
>> +    free_ep_req(loop->out_ep, loop->out_req);
>> +    usb_ep_free_request(loop->in_ep, loop->in_req);
>>  }
>>  
>>  static struct usb_function *loopback_alloc(struct usb_function_instance *fi)
>>
> 

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