diff options
| author | Felipe Balbi <felipe.balbi@linux.intel.com> | 2016-08-10 11:13:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-07 08:34:46 +0200 |
| commit | 07616b5a84b5f628ac03c2c9d84155f817490dc0 (patch) | |
| tree | 8dcc0a863d215ff4cdc3842800d2e1ce11f20ffb /drivers | |
| parent | 421f2109fa52802d2472d970bd3ec87b8485e5ba (diff) | |
| download | lwn-07616b5a84b5f628ac03c2c9d84155f817490dc0.tar.gz lwn-07616b5a84b5f628ac03c2c9d84155f817490dc0.zip | |
usb: dwc3: gadget: fix for short pkts during chained xfers
commit e5b36ae2f851024d43c76e51f395d32ce8d769ce upstream.
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: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index b65e583b6d9f..5a655b231af9 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1897,7 +1897,8 @@ 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; @@ -1905,6 +1906,19 @@ 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 @@ -1916,6 +1930,7 @@ 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) { @@ -1977,10 +1992,13 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep, int ret; do { + int chain; + req = next_request(&dep->started_list); if (WARN_ON_ONCE(!req)) return 1; + chain = req->request.num_mapped_sgs > 0; i = 0; do { slot = req->first_trb_index + i; @@ -1990,9 +2008,8 @@ 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); |