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>
---
Changes in v2:
- Remove unused variable
drivers/usb/dwc3/gadget.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 61b7bef98cf9..05dbeae1308a 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2686,7 +2686,6 @@ 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;
@@ -2702,16 +2701,13 @@ 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 +2716,7 @@ 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 +2734,6 @@ 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
