diff options
Diffstat (limited to 'drivers/usb/dwc3')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index fc059107c052..dd5945ca9c86 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -563,27 +563,7 @@ static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep) if (!list_empty(&dep->req_queued)) { dwc3_stop_active_transfer(dwc, dep->number); - /* - * NOTICE: We are violating what the Databook says about the - * EndTransfer command. Ideally we would _always_ wait for the - * EndTransfer Command Completion IRQ, but that's causing too - * much trouble synchronizing between us and gadget driver. - * - * We have discussed this with the IP Provider and it was - * suggested to giveback all requests here, but give HW some - * extra time to synchronize with the interconnect. We're using - * an arbitraty 100us delay for that. - * - * Note also that a similar handling was tested by Synopsys - * (thanks a lot Paul) and nothing bad has come out of it. - * In short, what we're doing is: - * - * - Issue EndTransfer WITH CMDIOC bit set - * - Wait 100us - * - giveback all requests to gadget driver - */ - udelay(100); - + /* - giveback all requests to gadget driver */ while (!list_empty(&dep->req_queued)) { req = next_request(&dep->req_queued); @@ -1875,6 +1855,25 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum) if (!dep->resource_index) return; + /* + * NOTICE: We are violating what the Databook says about the + * EndTransfer command. Ideally we would _always_ wait for the + * EndTransfer Command Completion IRQ, but that's causing too + * much trouble synchronizing between us and gadget driver. + * + * We have discussed this with the IP Provider and it was + * suggested to giveback all requests here, but give HW some + * extra time to synchronize with the interconnect. We're using + * an arbitraty 100us delay for that. + * + * Note also that a similar handling was tested by Synopsys + * (thanks a lot Paul) and nothing bad has come out of it. + * In short, what we're doing is: + * + * - Issue EndTransfer WITH CMDIOC bit set + * - Wait 100us + */ + cmd = DWC3_DEPCMD_ENDTRANSFER; cmd |= DWC3_DEPCMD_HIPRI_FORCERM | DWC3_DEPCMD_CMDIOC; cmd |= DWC3_DEPCMD_PARAM(dep->resource_index); @@ -1882,6 +1881,8 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum) ret = dwc3_send_gadget_ep_cmd(dwc, dep->number, cmd, ¶ms); WARN_ON_ONCE(ret); dep->resource_index = 0; + + udelay(100); } static void dwc3_stop_active_transfers(struct dwc3 *dwc) |