Commit a694f3fa authored by Felipe Balbi's avatar Felipe Balbi Committed by Sasha Levin

usb: dwc3: gadget: fix for short pkts during chained xfers

[ Upstream commit e5b36ae2 ]

DWC3 has one interesting peculiarity with chained
transfers. If we setup N chained transfers and we
get a short packet before processing all N TRBs,
DWC3 will (conditionally) issue a XferComplete or
XferInProgress event and retire all TRBs from the
one which got a short packet to the last without
clearing their HWO bits.

This means SW must clear HWO bit manually, which
this patch is doing.

Cc: <stable@vger.kernel.org>
Cc: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
parent 60b8bcfd
......@@ -1810,7 +1810,8 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
struct dwc3_request *req, struct dwc3_trb *trb,
const struct dwc3_event_depevt *event, int status)
const struct dwc3_event_depevt *event, int status,
int chain)
{
unsigned int count;
unsigned int s_pkt = 0;
......@@ -1818,6 +1819,19 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
trace_dwc3_complete_trb(dep, trb);
/*
* If we're in the middle of series of chained TRBs and we
* receive a short transfer along the way, DWC3 will skip
* through all TRBs including the last TRB in the chain (the
* where CHN bit is zero. DWC3 will also avoid clearing HWO
* bit and SW has to do it manually.
*
* We're going to do that here to avoid problems of HW trying
* to use bogus TRBs for transfers.
*/
if (chain && (trb->ctrl & DWC3_TRB_CTRL_HWO))
trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
/*
* We continue despite the error. There is not much we
......@@ -1829,6 +1843,7 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
*/
dev_err(dwc->dev, "%s's TRB (%p) still owned by HW\n",
dep->name, trb);
count = trb->size & DWC3_TRB_SIZE_MASK;
if (dep->direction) {
......@@ -1889,11 +1904,15 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
int ret;
do {
int chain;
req = next_request(&dep->req_queued);
if (!req) {
WARN_ON_ONCE(1);
return 1;
}
chain = req->request.num_mapped_sgs > 0;
i = 0;
do {
slot = req->start_slot + i;
......@@ -1904,9 +1923,8 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
trb = &dep->trb_pool[slot];
count += trb->size & DWC3_TRB_SIZE_MASK;
ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
event, status);
event, status, chain);
if (ret)
break;
} while (++i < req->request.num_mapped_sgs);
......
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