usb: dwc3: Fix missed isoc IN transaction

If an IN transfer is missed on isoc endpoint, then driver must insure
that next ep_queue is properly handled.
This patch fixes this issue by starting a new transfer for next queued
request.

Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 52 insertions, 24 deletions

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index e402022b9e15..fcb8be2ec1c9 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -405,6 +405,7 @@ struct dwc3_event_buffer {
  * @number: endpoint number (1 - 15)
  * @type: set to bmAttributes & USB_ENDPOINT_XFERTYPE_MASK
  * @res_trans_idx: Resource transfer index
+ * @current_uf: Current uf received through last event parameter
  * @interval: the intervall on which the ISOC transfer is started
  * @name: a human readable name e.g. ep1out-bulk
  * @direction: true for TX, false for RX
@@ -428,6 +429,7 @@ struct dwc3_ep {
 #define DWC3_EP_WEDGE           (1 << 2)
 #define DWC3_EP_BUSY            (1 << 4)
 #define DWC3_EP_PENDING_REQUEST (1 << 5)
+#define DWC3_EP_MISSED_ISOC     (1 << 6)
 
         /* This last one is specific to EP0 */
 #define DWC3_EP0_DIR_IN         (1 << 31)
@@ -437,6 +439,7 @@ struct dwc3_ep {
         u8                      number;
         u8                      type;
         u8                      res_trans_idx;
+        u16                     current_uf;
         u32                     interval;
 
         char                    name[20];
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index be87e82b36c7..0cab69e51380 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -990,6 +990,34 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param,
         return 0;
 }
 
+static void __dwc3_gadget_start_isoc(struct dwc3 *dwc,
+                struct dwc3_ep *dep, u32 cur_uf)
+{
+        u32 uf;
+
+        if (list_empty(&dep->request_list)) {
+                dev_vdbg(dwc->dev, "ISOC ep %s run out for requests.\n",
+                        dep->name);
+                return;
+        }
+
+        /* 4 micro frames in the future */
+        uf = cur_uf + dep->interval * 4;
+
+        __dwc3_gadget_kick_transfer(dep, uf, 1);
+}
+
+static void dwc3_gadget_start_isoc(struct dwc3 *dwc,
+                struct dwc3_ep *dep, const struct dwc3_event_depevt *event)
+{
+        u32 cur_uf, mask;
+
+        mask = ~(dep->interval - 1);
+        cur_uf = event->parameters & mask;
+
+        __dwc3_gadget_start_isoc(dwc, dep, cur_uf);
+}
+
 static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 {
         struct dwc3             *dwc = dep->dwc;
@@ -1019,8 +1047,14 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 
         list_add_tail(&req->list, &dep->request_list);
 
-        if (usb_endpoint_xfer_isoc(dep->endpoint.desc) && (dep->flags & DWC3_EP_BUSY))
-                dep->flags |= DWC3_EP_PENDING_REQUEST;
+        if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
+                if (dep->flags & DWC3_EP_BUSY) {
+                        dep->flags |= DWC3_EP_PENDING_REQUEST;
+                } else if (dep->flags & DWC3_EP_MISSED_ISOC) {
+                        __dwc3_gadget_start_isoc(dwc, dep, dep->current_uf);
+                        dep->flags &= ~DWC3_EP_MISSED_ISOC;
+                }
+        }
 
         /*
          * There are two special cases:
@@ -1591,6 +1625,7 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
         struct dwc3_trb         *trb;
         unsigned int            count;
         unsigned int            s_pkt = 0;
+        unsigned int            trb_status;
 
         do {
                 req = next_request(&dep->req_queued);
@@ -1616,9 +1651,18 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
 
                 if (dep->direction) {
                         if (count) {
-                                dev_err(dwc->dev, "incomplete IN transfer %s\n",
-                                                dep->name);
-                                status = -ECONNRESET;
+                                trb_status = DWC3_TRB_SIZE_TRBSTS(trb->size);
+                                if (trb_status == DWC3_TRBSTS_MISSED_ISOC) {
+                                        dev_dbg(dwc->dev, "incomplete IN transfer %s\n",
+                                                        dep->name);
+                                        dep->current_uf = event->parameters &
+                                                ~(dep->interval - 1);
+                                        dep->flags |= DWC3_EP_MISSED_ISOC;
+                                } else {
+                                        dev_err(dwc->dev, "incomplete IN transfer %s\n",
+                                                        dep->name);
+                                        status = -ECONNRESET;
+                                }
                         }
                 } else {
                         if (count && (event->status & DEPEVT_STATUS_SHORT))
@@ -1690,25 +1734,6 @@ static void dwc3_endpoint_transfer_complete(struct dwc3 *dwc,
         }
 }
 
-static void dwc3_gadget_start_isoc(struct dwc3 *dwc,
-                struct dwc3_ep *dep, const struct dwc3_event_depevt *event)
-{
-        u32 uf, mask;
-
-        if (list_empty(&dep->request_list)) {
-                dev_vdbg(dwc->dev, "ISOC ep %s run out for requests.\n",
-                        dep->name);
-                return;
-        }
-
-        mask = ~(dep->interval - 1);
-        uf = event->parameters & mask;
-        /* 4 micro frames in the future */
-        uf += dep->interval * 4;
-
-        __dwc3_gadget_kick_transfer(dep, uf, 1);
-}
-
 static void dwc3_process_ep_cmd_complete(struct dwc3_ep *dep,
                 const struct dwc3_event_depevt *event)
 {