We had a 100us delay to synchronize the END_TRANSFER command completion before giving back requests to the function drivers. Now, the controller driver can handle cancelled TRBs with the requests' cancelled_list and it can also wait until the END_TRANSFER completion before starting new transfers. Synchronization can simply base on the controller's command completion interrupt. The 100us delay is no longer needed. Remove this arbitrary delay. Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx> --- drivers/usb/dwc3/gadget.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 61b7bef98cf9..fe9a7e37725c 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2702,16 +2702,13 @@ static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, * 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 arbitrary 100us delay for that. + * suggested to giveback all requests here. * * 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 + * In short, what we're doing is issuing EndTransfer with + * CMDIOC bit set and delay kicking transfer until the + * EndTransfer command had completed. * * As of IP version 3.10a of the DWC_usb3 IP, the controller * supports a mode to work around the above limitation. The @@ -2720,8 +2717,7 @@ static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, * by writing GUCTL2[14]. This polling is already done in the * dwc3_send_gadget_ep_cmd() function so if the mode is * enabled, the EndTransfer command will have completed upon - * returning from this function and we don't need to delay for - * 100us. + * returning from this function. * * This mode is NOT available on the DWC_usb31 IP. */ @@ -2739,9 +2735,6 @@ static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, dep->flags &= ~DWC3_EP_TRANSFER_STARTED; else dep->flags |= DWC3_EP_END_TRANSFER_PENDING; - - if (dwc3_is_usb31(dwc) || dwc->revision < DWC3_REVISION_310A) - udelay(100); } static void dwc3_clear_stall_all_ep(struct dwc3 *dwc) -- 2.11.0
