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

[Krzysztof Opasiak]

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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