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>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 194cafdac16af40e95219faac0feeec5a1f673b4..97076015b41c99ba5bec612af6cc64034840bfef 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -614,7 +614,6 @@ struct dwc3 {
        unsigned                three_stage_setup:1;
        unsigned                ep0_bounced:1;
        unsigned                ep0_expect_in:1;
-       unsigned                start_config_issued:1;
        unsigned                setup_packet_pending:1;
        unsigned                delayed_status:1;
        unsigned                needs_fifo_resize:1;

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 7c0eaeb577d5ddc958e0b98bf9d8941147c6a226..b6051f3960153b4617e79da744532df072c9b5b8 100644 (file)
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -442,7 +442,6 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
        u32 cfg;
        int ret;
 
-       dwc->start_config_issued = false;
        cfg = le16_to_cpu(ctrl->wValue);
 
        switch (dwc->dev_state) {
@@ -496,10 +495,6 @@ static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
                dev_vdbg(dwc->dev, "USB_REQ_SET_CONFIGURATION\n");
                ret = dwc3_ep0_set_config(dwc, ctrl);
                break;
-       case USB_REQ_SET_INTERFACE:
-               dev_vdbg(dwc->dev ,"USB_REQ_SET_INTERFACE");
-               dwc->start_config_issued = false;
-               /* Fall through */
        default:
                dev_vdbg(dwc->dev, "Forwarding to gadget driver\n");
                ret = dwc3_ep0_delegate_req(dwc, ctrl);

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index b43c6f90b25ff1263715a8533b2ab79ca9571e13..fba74f8a5b5a5d521d81c11f4c5784c425c34751 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -359,24 +359,66 @@ 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;
@@ -471,10 +513,6 @@ 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->desc = desc;
                dep->comp_desc = comp_desc;
                dep->type = usb_endpoint_type(desc);
@@ -1375,8 +1413,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
        reg |= dwc->maximum_speed;
        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);
 
@@ -1861,7 +1897,6 @@ 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;
        dwc->setup_packet_pending = false;
@@ -1949,7 +1984,6 @@ 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);