usb: dwc3: Add ENDXFER command polling
ENDXFER polling is available on version 3.10a and later of the
DWC_usb3 (USB 3.0) controller. With this feature, the software can poll
the CMDACT bit in the DEPCMD register after issuing an ENDXFER command.
This feature is enabled by writing GUCTL2[14].
This feature is NOT available on the DWC_usb31 (USB 3.1) IP.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0288ea9..161a6bf 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2228,6 +2228,18 @@
*
* - Issue EndTransfer WITH CMDIOC bit set
* - Wait 100us
+ *
+ * As of IP version 3.10a of the DWC_usb3 IP, the controller
+ * supports a mode to work around the above limitation. The
+ * software can poll the CMDACT bit in the DEPCMD register
+ * after issuing a EndTransfer command. This mode is enabled
+ * 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.
+ *
+ * This mode is NOT available on the DWC_usb31 IP.
*/
cmd = DWC3_DEPCMD_ENDTRANSFER;
@@ -2239,7 +2251,9 @@
WARN_ON_ONCE(ret);
dep->resource_index = 0;
dep->flags &= ~DWC3_EP_BUSY;
- udelay(100);
+
+ if (dwc3_is_usb31(dwc) || dwc->revision < DWC3_REVISION_310A)
+ udelay(100);
}
static void dwc3_stop_active_transfers(struct dwc3 *dwc)