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| author | Felipe Balbi <felipe.balbi@linux.intel.com> | 2016-08-10 11:13:26 +0300 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-08-31 19:32:09 -0400 |
| commit | de72ed191825536e27049f353526d7977f4995dc (patch) | |
| tree | 1a9fae52ed552f794c1db98174527a64a3850a4b /drivers/usb | |
| parent | 9bf46c6c417470a5072e2529c634a80ff2e9a890 (diff) | |
| download | lwn-de72ed191825536e27049f353526d7977f4995dc.tar.gz lwn-de72ed191825536e27049f353526d7977f4995dc.zip | |
usb: dwc3: gadget: fix for short pkts during chained xfers
[ Upstream commit e5b36ae2f851024d43c76e51f395d32ce8d769ce ]
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: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 78722a4f4fe0..ec6440ff73c2 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1802,7 +1802,8 @@ 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; @@ -1810,6 +1811,19 @@ 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 @@ -1821,6 +1835,7 @@ 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) { @@ -1881,11 +1896,15 @@ 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; @@ -1896,9 +1915,8 @@ 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); |