Commit cf2f8b63 authored by Thinh Nguyen's avatar Thinh Nguyen Committed by Greg Kroah-Hartman
Browse files

usb: dwc3: gadget: Remove END_TRANSFER delay 



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: default avatarThinh Nguyen <thinhn@synopsys.com>
Signed-off-by: default avatarFelipe Balbi <balbi@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent da10bcdd

drivers/usb/dwc3/gadget.c

+5 −13
Original line number Diff line number Diff line
@@ -2693,7 +2693,6 @@ static void dwc3_reset_gadget(struct dwc3 *dwc) 
static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,

	bool interrupt)

{

	struct dwc3 *dwc = dep->dwc;

	struct dwc3_gadget_ep_cmd_params params;

	u32 cmd;

	int ret;
@@ -2709,16 +2708,13 @@ 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
@@ -2727,8 +2723,7 @@ 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.

	 */
@@ -2746,9 +2741,6 @@ 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)