Revert "usb: xhci: Limit Stop Endpoint retries"

This reverts commit ae1a08850a which is
commit 42b7581376015c1bbcbe5831f043cd0ac119d028 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Id33b40e8d8ba8ba5c0cdb624f60a4ec630a106da
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/usb/host/xhci-ring.c

@@ -52,7 +52,6 @@
  *   endpoint rings; it generates events on the event ring for these.
  */
 
-#include <linux/jiffies.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
@@ -1158,35 +1157,16 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id,
 			return;
 		case EP_STATE_STOPPED:
 			/*
-			 * Per xHCI 4.6.9, Stop Endpoint command on a Stopped
+			 * NEC uPD720200 sometimes sets this state and fails with
-			 * EP is a Context State Error, and EP stays Stopped.
+			 * Context Error while continuing to process TRBs.
-			 *
+			 * Be conservative and trust EP_CTX_STATE on other chips.
-			 * But maybe it failed on Halted, and somebody ran Reset
-			 * Endpoint later. EP state is now Stopped and EP_HALTED
-			 * still set because Reset EP handler will run after us.
-			 */
-			if (ep->ep_state & EP_HALTED)
-				break;
-			/*
-			 * On some HCs EP state remains Stopped for some tens of
-			 * us to a few ms or more after a doorbell ring, and any
-			 * new Stop Endpoint fails without aborting the restart.
-			 * This handler may run quickly enough to still see this
-			 * Stopped state, but it will soon change to Running.
-			 *
-			 * Assume this bug on unexpected Stop Endpoint failures.
-			 * Keep retrying until the EP starts and stops again, on
-			 * chips where this is known to help. Wait for 100ms.
 			 */
 			if (!(xhci->quirks & XHCI_NEC_HOST))
 				break;
-			if (time_is_before_jiffies(ep->stop_time + msecs_to_jiffies(100)))
-				break;
 			fallthrough;
 		case EP_STATE_RUNNING:
 			/* Race, HW handled stop ep cmd before ep was running */
-			xhci_dbg(xhci, "Stop ep completion ctx error, ctx_state %d\n",
+			xhci_dbg(xhci, "Stop ep completion ctx error, ep is running\n");
-					GET_EP_CTX_STATE(ep_ctx));
 
 			command = xhci_alloc_command(xhci, false, GFP_ATOMIC);
 			if (!command) {

drivers/usb/host/xhci.c

@@ -8,7 +8,6 @@
  * Some code borrowed from the Linux EHCI driver.
  */
 
-#include <linux/jiffies.h>
 #include <linux/pci.h>
 #ifndef __GENKSYMS__	/* ANDROID: KABI CRC preservation hack */
 #include <linux/iommu.h>
@@ -1929,7 +1928,6 @@ static int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 			ret = -ENOMEM;
 			goto done;
 		}
-		ep->stop_time = jiffies;
 		ep->ep_state |= EP_STOP_CMD_PENDING;
 		xhci_queue_stop_endpoint(xhci, command, urb->dev->slot_id,
 					 ep_index, 0);

drivers/usb/host/xhci.h

@@ -971,7 +971,6 @@ struct xhci_virt_ep {
 	/* Bandwidth checking storage */
 	struct xhci_bw_info	bw_info;
 	struct list_head	bw_endpoint_list;
-	unsigned long		stop_time;
 	/* Isoch Frame ID checking storage */
 	int			next_frame_id;
 	/* Use new Isoch TRB layout needed for extended TBC support */