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usb: dwc3: ep0: fix for dead code 

commit 6856d30 (usb: dwc3: ep0: return early
on NULL requests) tried to fix a minor corner
case where we could dereference a NULL pointer
but it also ended up introducing some dead code.

Unfortunately, that dead code, if reached, could
end up starving the endpoint request list because
a request would never be given back when it should.

Fix this by moving the check for empty request list
before its first use.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Felipe Balbi 2014-11-10 14:39:44 -06:00
parent 206c5f60a3
commit 520fe76336
1 changed files with 4 additions and 4 deletions
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8
drivers/usb/dwc3/ep0.c
View File

@ -791,6 +791,10 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
trb = dwc->ep0_trb;
r = next_request(&ep0->request_list);
if (!r)
return;
status = DWC3_TRB_SIZE_TRBSTS(trb->size);
if (status == DWC3_TRBSTS_SETUP_PENDING) {
dwc3_trace(trace_dwc3_ep0, "Setup Pending received");
@ -801,10 +805,6 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
return;
}
r = next_request(&ep0->request_list);
if (!r)
return;
ur = &r->request;
length = trb->size & DWC3_TRB_SIZE_MASK;