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.
>
>> /*
>> * SOURCE/SINK FUNCTION ... a primary testing vehicle for USB peripheral
>> * controller drivers.
>> @@ -51,6 +53,11 @@ struct f_sourcesink {
>> struct usb_ep *iso_out_ep;
>> int cur_alt;
>>
>> + struct usb_request *in_req;
>> + struct usb_request *out_req;
>> + struct usb_request *iso_in_req[REQ_CNT];
>> + struct usb_request *iso_out_req[REQ_CNT];
>> +
>> unsigned pattern;
>> unsigned isoc_interval;
>> unsigned isoc_maxpacket;
>> @@ -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?
I've only changed place where requests are freed. Now they are freed in
sourcesink_disable(). The current code is even more memory leak
resistant, because requests will be freed even in case of failure of
usb_ep_queue() in source_sink_complete(), which was not provided so far.
>> return;
>>
>> case -EOVERFLOW: /* buffer overrun on read means that
>> @@ -613,7 +619,7 @@ static int source_sink_start_ep(struct f_sourcesink *ss, bool is_in,
>> ep = is_in ? ss->in_ep : ss->out_ep;
>> }
>>
>> - for (i = 0; i < 8; i++) {
>> + for (i = 0; i < REQ_CNT; i++) {
>> req = ss_alloc_ep_req(ep, size);
>> if (!req)
>> return -ENOMEM;
>> @@ -635,8 +641,18 @@ static int source_sink_start_ep(struct f_sourcesink *ss, bool is_in,
>> free_ep_req(ep, req);
>> }
>>
>> - if (!is_iso)
>> + if (is_iso) {
>> + if (is_in)
>> + ss->iso_in_req[i] = req;
>> + else
>> + ss->iso_out_req[i] = req;
>> + } else {
>> + if (is_in)
>> + ss->in_req = req;
>> + else
>> + ss->out_req = req;
>
> The req will be different for both bulk and iso, why you only
> have array for iso requests?
Because only for iso endpoints there is allocated more than one request.
I don't know why, but I've decided to not change this.
>
>> break;
>> + }
>> }
>>
>> return status;
>> @@ -764,8 +780,19 @@ static int sourcesink_get_alt(struct usb_function *f, unsigned intf)
>> static void sourcesink_disable(struct usb_function *f)
>> {
>> struct f_sourcesink *ss = func_to_ss(f);
>> + int i;
>>
>> disable_source_sink(ss);
>> +
>> + free_ep_req(ss->in_ep, ss->in_req);
>> + free_ep_req(ss->out_ep, ss->out_req);
>> +
>> + if (ss->iso_in_ep) {
>> + for (i = 0; i < REQ_CNT; i++) {
>> + free_ep_req(ss->iso_in_ep, ss->iso_in_req[i]);
>> + free_ep_req(ss->iso_out_ep, ss->iso_out_req[i]);
>> + }
>> + }
>> }
>>
>> /*-------------------------------------------------------------------------*/
>> --
>> 1.9.1
>>
>> --
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>
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