Re: [PATCH 03/23] usb: gadget: f_sourcesink: free requests in sourcesink_disable()

From: Krzysztof Opasiak
Date: Fri Nov 06 2015 - 04:58:50 EST

On 11/06/2015 10:48 AM, Peter Chen wrote:
On Fri, Nov 06, 2015 at 09:50:11AM +0100, Robert Baldyga wrote:
On 11/06/2015 09:15 AM, Peter Chen wrote:
On Tue, Nov 03, 2015 at 01:53:42PM +0100, Robert Baldyga wrote:
USB requests in SourceSink function are allocated in sourcesink_get_alt()
function, so we prefer to free them rather in sourcesink_disable() than
in source_sink_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_sourcesink.c | 33 +++++++++++++++++++++++++++---
1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/f_sourcesink.c b/drivers/usb/gadget/function/f_sourcesink.c
index a8b68c6..d8f5f56 100644
--- a/drivers/usb/gadget/function/f_sourcesink.c
+++ b/drivers/usb/gadget/function/f_sourcesink.c
@@ -22,6 +22,8 @@
#include "g_zero.h"
#include "u_f.h"

+#define REQ_CNT 8

It would be buffer if we can have module parameter for this like
qlen at f_loopback.
@@ -561,7 +568,6 @@ static void source_sink_complete(struct usb_ep *ep, struct usb_request *req)
req->actual, req->length);
if (ep == ss->out_ep)
check_read_data(ss, req);
- free_ep_req(ep, req);

I find the current code may cause memory leak, since above code
is only called one time.

I don't see what you mean. Can you explain a bit more in which situation
can memory leak take place?

Oh, sorry, I have not seen there is a "break;" at the source_sink_start_ep for
none-iso endpoint, so, I am wrong, no memory leak here.

I have tried changing bulk for 8 requests, the performance improves
greatly, but still a little problem for OUT, I will see what's the matter.
Besides, it will be better we can have a qlen parameters like f_loopback,
in that case, we can improve the performance for gadget, and get the best performance
when testing with usbtest, I will do it later.

Moreover, I would suggest to add qlen and iso_qlen params not only qlen as even now we are using different qlen for bulk and iso.

Best regards,
Krzysztof Opasiak
Samsung R&D Institute Poland
Samsung Electronics
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