Re: CSW endpoint status returned STALL after BOT MSC Reset

[Alan Stern]

On Wed, 30 Oct 2013, Alan Stern wrote:

> I think you have found a bug in the dwc3 driver.

> At this point, because the IGNORE_BULK_OUT bit is set, g_mass_storage
> issues a usb_ep_clear_halt() call for the bulk-in (CSW) endpoint.  
> This tells the dwc3 driver to change the endpoint's status back to 0:
> 
>               if (test_and_clear_bit(IGNORE_BULK_OUT,
>                                      &common->fsg->atomic_bitflags))
>                       usb_ep_clear_halt(common->fsg->bulk_in);
> 
> > INFO        Retrieving status on CBW endpoint
> > INFO        CBW endpoint status = 0x0
> > INFO        Retrieving status on CSW endpoint
> > INFO        CSW endpoint status = 0x1
> 
> But the status is still set to 1.  Clearly this is a bug in dwc3.

And indeed it is.  The dwc3 driver does not implement the wedge method 
correctly.  This patch should fix it.  Let me know how it works.

Alan Stern



Index: usb-3.12/drivers/usb/dwc3/ep0.c
===================================================================
--- usb-3.12.orig/drivers/usb/dwc3/ep0.c
+++ usb-3.12/drivers/usb/dwc3/ep0.c
@@ -459,6 +459,8 @@ static int dwc3_ep0_handle_feature(struc
                        dep = dwc3_wIndex_to_dep(dwc, wIndex);
                        if (!dep)
                                return -EINVAL;
+                       if (set == 0 && (dep->flags & DWC3_EP_WEDGE))
+                               break;
                        ret = __dwc3_gadget_ep_set_halt(dep, set);
                        if (ret)
                                return -EINVAL;
Index: usb-3.12/drivers/usb/dwc3/gadget.c
===================================================================
--- usb-3.12.orig/drivers/usb/dwc3/gadget.c
+++ usb-3.12/drivers/usb/dwc3/gadget.c
@@ -1200,9 +1200,6 @@ int __dwc3_gadget_ep_set_halt(struct dwc
                else
                        dep->flags |= DWC3_EP_STALL;
        } else {
-               if (dep->flags & DWC3_EP_WEDGE)
-                       return 0;
-
                ret = dwc3_send_gadget_ep_cmd(dwc, dep->number,
                        DWC3_DEPCMD_CLEARSTALL, &params);
                if (ret)
@@ -1210,7 +1207,7 @@ int __dwc3_gadget_ep_set_halt(struct dwc
                                        value ? "set" : "clear",
                                        dep->name);
                else
-                       dep->flags &= ~DWC3_EP_STALL;
+                       dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
        }
 
        return ret;

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