usb: dwc3: Fix assignment of EP transfer resources

[pandora-kernel.git] / drivers / usb / dwc3 / gadget.c

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index b4623f1..392222b 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -229,24 +229,66 @@ static void dwc3_free_trb_pool(struct dwc3_ep *dep)
        dep->trb_pool_dma = 0;
 }
 
+static int dwc3_gadget_set_xfer_resource(struct dwc3 *dwc, struct dwc3_ep *dep);
+
+/**
+ * dwc3_gadget_start_config - Configure EP resources
+ * @dwc: pointer to our controller context structure
+ * @dep: endpoint that is being enabled
+ *
+ * The assignment of transfer resources cannot perfectly follow the
+ * data book due to the fact that the controller driver does not have
+ * all knowledge of the configuration in advance. It is given this
+ * information piecemeal by the composite gadget framework after every
+ * SET_CONFIGURATION and SET_INTERFACE. Trying to follow the databook
+ * programming model in this scenario can cause errors. For two
+ * reasons:
+ *
+ * 1) The databook says to do DEPSTARTCFG for every SET_CONFIGURATION
+ * and SET_INTERFACE (8.1.5). This is incorrect in the scenario of
+ * multiple interfaces.
+ *
+ * 2) The databook does not mention doing more DEPXFERCFG for new
+ * endpoint on alt setting (8.1.6).
+ *
+ * The following simplified method is used instead:
+ *
+ * All hardware endpoints can be assigned a transfer resource and this
+ * setting will stay persistent until either a core reset or
+ * hibernation. So whenever we do a DEPSTARTCFG(0) we can go ahead and
+ * do DEPXFERCFG for every hardware endpoint as well. We are
+ * guaranteed that there are as many transfer resources as endpoints.
+ *
+ * This function is called for each endpoint when it is being enabled
+ * but is triggered only when called for EP0-out, which always happens
+ * first, and which should only happen in one of the above conditions.
+ */
 static int dwc3_gadget_start_config(struct dwc3 *dwc, struct dwc3_ep *dep)
 {
        struct dwc3_gadget_ep_cmd_params params;
        u32                     cmd;
+       int                     i;
+       int                     ret;
+
+       if (dep->number)
+               return 0;
 
        memset(&params, 0x00, sizeof(params));
+       cmd = DWC3_DEPCMD_DEPSTARTCFG;
 
-       if (dep->number != 1) {
-               cmd = DWC3_DEPCMD_DEPSTARTCFG;
-               /* XferRscIdx == 0 for ep0 and 2 for the remaining */
-               if (dep->number > 1) {
-                       if (dwc->start_config_issued)
-                               return 0;
-                       dwc->start_config_issued = true;
-                       cmd |= DWC3_DEPCMD_PARAM(2);
-               }
+       ret = dwc3_send_gadget_ep_cmd(dwc, 0, cmd, &params);
+       if (ret)
+               return ret;
 
-               return dwc3_send_gadget_ep_cmd(dwc, 0, cmd, &params);
+       for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
+               struct dwc3_ep *dep = dwc->eps[i];
+
+               if (!dep)
+                       continue;
+
+               ret = dwc3_gadget_set_xfer_resource(dwc, dep);
+               if (ret)
+                       return ret;
        }
 
        return 0;
@@ -340,10 +382,6 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
                struct dwc3_trb_hw      *trb_link_hw;
                struct dwc3_trb         trb_link;
 
-               ret = dwc3_gadget_set_xfer_resource(dwc, dep);
-               if (ret)
-                       return ret;
-
                dep->desc = desc;
                dep->type = usb_endpoint_type(desc);
                dep->flags |= DWC3_EP_ENABLED;
@@ -1185,8 +1223,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
        reg |= DWC3_DCFG_SUPERSPEED;
        dwc3_writel(dwc->regs, DWC3_DCFG, reg);
 
-       dwc->start_config_issued = false;
-
        /* Start with SuperSpeed Default */
        dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
 
@@ -1640,7 +1676,6 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
 
        dwc3_stop_active_transfers(dwc);
        dwc3_disconnect_gadget(dwc);
-       dwc->start_config_issued = false;
 
        dwc->gadget.speed = USB_SPEED_UNKNOWN;
 }
@@ -1692,7 +1727,6 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 
        dwc3_stop_active_transfers(dwc);
        dwc3_clear_stall_all_ep(dwc);
-       dwc->start_config_issued = false;
 
        /* Reset device address to zero */
        reg = dwc3_readl(dwc->regs, DWC3_DCFG);