usb: dwc3: Fix assignment of EP transfer resources

commit c450960187f45d4260db87c7dd4fc0bceb5565d8 upstream.

The assignement of EP transfer resources was not handled properly in the
dwc3 driver. Commit aebda6187181 ("usb: dwc3: Reset the transfer
resource index on SET_INTERFACE") previously fixed one aspect of this
where resources may be exhausted with multiple calls to SET_INTERFACE.
However, it introduced an issue where composite devices with multiple
interfaces can be assigned the same transfer resources for different
endpoints. This patch solves both issues.

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 patch triggers off of the calling dwc3_gadget_start_config() for
EP0-out, which always happens first, and which should only happen in one
of the above conditions.

Fixes: aebda6187181 ("usb: dwc3: Reset the transfer resource index on SET_INTERFACE")
Reported-by: Ravi Babu <ravibabu@ti.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 36f1cb74588c5b7bff230e3ed91e42f73c3b47e8..78be201d81f4eabe0ec6d75e95cf3d76e8aef9db 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -853,7 +853,6 @@ struct dwc3 {
        unsigned                pullups_connected:1;
        unsigned                resize_fifos:1;
        unsigned                setup_packet_pending:1;
-       unsigned                start_config_issued:1;
        unsigned                three_stage_setup:1;
        unsigned                usb3_lpm_capable:1;
 

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 5320e939e0902647edb21a5e55d7e537c1b03b33..b13912d5fa995f463a93b14c521888cee77541c5 100644 (file)
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -555,7 +555,6 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
        int ret;
        u32 reg;
 
-       dwc->start_config_issued = false;
        cfg = le16_to_cpu(ctrl->wValue);
 
        switch (state) {
@@ -737,10 +736,6 @@ static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
                dwc3_trace(trace_dwc3_ep0, "USB_REQ_SET_ISOCH_DELAY");
                ret = dwc3_ep0_set_isoch_delay(dwc, ctrl);
                break;
-       case USB_REQ_SET_INTERFACE:
-               dwc3_trace(trace_dwc3_ep0, "USB_REQ_SET_INTERFACE");
-               dwc->start_config_issued = false;
-               /* Fall through */
        default:
                dwc3_trace(trace_dwc3_ep0, "Forwarding to gadget driver");
                ret = dwc3_ep0_delegate_req(dwc, ctrl);

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index a58376fd65fe6d788fa817d5600696bfd431c791..69ffe6e8d77fc0421fcbbd5826e0e70ca8d99966 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -388,24 +388,66 @@ 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;
@@ -519,10 +561,6 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
                struct dwc3_trb *trb_st_hw;
                struct dwc3_trb *trb_link;
 
-               ret = dwc3_gadget_set_xfer_resource(dwc, dep);
-               if (ret)
-                       return ret;
-
                dep->endpoint.desc = desc;
                dep->comp_desc = comp_desc;
                dep->type = usb_endpoint_type(desc);
@@ -1604,8 +1642,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
        }
        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);
 
@@ -2202,7 +2238,6 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
        dwc3_writel(dwc->regs, DWC3_DCTL, reg);
 
        dwc3_disconnect_gadget(dwc);
-       dwc->start_config_issued = false;
 
        dwc->gadget.speed = USB_SPEED_UNKNOWN;
        dwc->setup_packet_pending = false;
@@ -2253,7 +2288,6 @@ 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);