[PATCH v2 03/29] usb: gadget: f_loopback: free requests in loopback_disable()

From: Robert Baldyga
Date: Fri Nov 27 2015 - 06:00:30 EST


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.

Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
---
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 23933bd..7d1fa10 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)
--
1.9.1

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