xhci: remove CONFIG_USB_XHCI_HCD_DEBUGGING and unused code

CONFIG_USB_XHCI_HCD_DEBUGGING option is used to enable
verbose debugging output for the xHCI host controller
driver.

In the current version of the xhci-hcd driver, this
option must be turned on, in order for the debugging
log messages to be displayed, and users may need to
recompile the linux kernel to obtain debugging
information that will help them track down problems.

This patch removes the above debug option to enable
debugging log messages at all times.
The aim of this is to rely on the debugfs and the
dynamic debugging feature for fine-grained management
of debugging messages and to not force users to set
the debug config option and compile the linux kernel
in order to have access in that information.

This patch, also, removes the XHCI_DEBUG symbol and the
functions dma_to_stream_ring(), xhci_test_radix_tree()
and xhci_event_ring_work() that are not useful anymore.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/Kconfig

@@ -29,15 +29,6 @@ if USB_XHCI_HCD
 config USB_XHCI_PLATFORM
 	tristate
 
-config USB_XHCI_HCD_DEBUGGING
-	bool "Debugging for the xHCI host controller"
-	---help---
-	  Say 'Y' to turn on debugging for the xHCI host controller driver.
-	  This will spew debugging output, even in interrupt context.
-	  This should only be used for debugging xHCI driver bugs.
-
-	  If unsure, say N.
-
 endif # USB_XHCI_HCD
 
 config USB_EHCI_HCD

drivers/usb/host/xhci-mem.c

@@ -481,17 +481,6 @@ struct xhci_ring *xhci_dma_to_transfer_ring(
 	return ep->ring;
 }
 
-/* Only use this when you know stream_info is valid */
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-static struct xhci_ring *dma_to_stream_ring(
-		struct xhci_stream_info *stream_info,
-		u64 address)
-{
-	return radix_tree_lookup(&stream_info->trb_address_map,
-			address >> TRB_SEGMENT_SHIFT);
-}
-#endif	/* CONFIG_USB_XHCI_HCD_DEBUGGING */
-
 struct xhci_ring *xhci_stream_id_to_ring(
 		struct xhci_virt_device *dev,
 		unsigned int ep_index,
@@ -509,58 +498,6 @@ struct xhci_ring *xhci_stream_id_to_ring(
 	return ep->stream_info->stream_rings[stream_id];
 }
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-static int xhci_test_radix_tree(struct xhci_hcd *xhci,
-		unsigned int num_streams,
-		struct xhci_stream_info *stream_info)
-{
-	u32 cur_stream;
-	struct xhci_ring *cur_ring;
-	u64 addr;
-
-	for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
-		struct xhci_ring *mapped_ring;
-		int trb_size = sizeof(union xhci_trb);
-
-		cur_ring = stream_info->stream_rings[cur_stream];
-		for (addr = cur_ring->first_seg->dma;
-				addr < cur_ring->first_seg->dma + TRB_SEGMENT_SIZE;
-				addr += trb_size) {
-			mapped_ring = dma_to_stream_ring(stream_info, addr);
-			if (cur_ring != mapped_ring) {
-				xhci_warn(xhci, "WARN: DMA address 0x%08llx "
-						"didn't map to stream ID %u; "
-						"mapped to ring %p\n",
-						(unsigned long long) addr,
-						cur_stream,
-						mapped_ring);
-				return -EINVAL;
-			}
-		}
-		/* One TRB after the end of the ring segment shouldn't return a
-		 * pointer to the current ring (although it may be a part of a
-		 * different ring).
-		 */
-		mapped_ring = dma_to_stream_ring(stream_info, addr);
-		if (mapped_ring != cur_ring) {
-			/* One TRB before should also fail */
-			addr = cur_ring->first_seg->dma - trb_size;
-			mapped_ring = dma_to_stream_ring(stream_info, addr);
-		}
-		if (mapped_ring == cur_ring) {
-			xhci_warn(xhci, "WARN: Bad DMA address 0x%08llx "
-					"mapped to valid stream ID %u; "
-					"mapped ring = %p\n",
-					(unsigned long long) addr,
-					cur_stream,
-					mapped_ring);
-			return -EINVAL;
-		}
-	}
-	return 0;
-}
-#endif	/* CONFIG_USB_XHCI_HCD_DEBUGGING */
-
 /*
  * Change an endpoint's internal structure so it supports stream IDs.  The
  * number of requested streams includes stream 0, which cannot be used by device
@@ -687,13 +624,6 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
 	 * was any other way, the host controller would assume the ring is
 	 * "empty" and wait forever for data to be queued to that stream ID).
 	 */
-#if XHCI_DEBUG
-	/* Do a little test on the radix tree to make sure it returns the
-	 * correct values.
-	 */
-	if (xhci_test_radix_tree(xhci, num_streams, stream_info))
-		goto cleanup_rings;
-#endif
 
 	return stream_info;
 

drivers/usb/host/xhci.c

@@ -528,57 +528,6 @@ int xhci_init(struct usb_hcd *hcd)
 /*-------------------------------------------------------------------------*/
 
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-static void xhci_event_ring_work(unsigned long arg)
-{
-	unsigned long flags;
-	int temp;
-	u64 temp_64;
-	struct xhci_hcd *xhci = (struct xhci_hcd *) arg;
-	int i, j;
-
-	xhci_dbg(xhci, "Poll event ring: %lu\n", jiffies);
-
-	spin_lock_irqsave(&xhci->lock, flags);
-	temp = xhci_readl(xhci, &xhci->op_regs->status);
-	xhci_dbg(xhci, "op reg status = 0x%x\n", temp);
-	if (temp == 0xffffffff || (xhci->xhc_state & XHCI_STATE_DYING) ||
-			(xhci->xhc_state & XHCI_STATE_HALTED)) {
-		xhci_dbg(xhci, "HW died, polling stopped.\n");
-		spin_unlock_irqrestore(&xhci->lock, flags);
-		return;
-	}
-
-	temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
-	xhci_dbg(xhci, "ir_set 0 pending = 0x%x\n", temp);
-	xhci_dbg(xhci, "HC error bitmask = 0x%x\n", xhci->error_bitmask);
-	xhci->error_bitmask = 0;
-	xhci_dbg(xhci, "Event ring:\n");
-	xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
-	xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
-	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
-	temp_64 &= ~ERST_PTR_MASK;
-	xhci_dbg(xhci, "ERST deq = 64'h%0lx\n", (long unsigned int) temp_64);
-	xhci_dbg(xhci, "Command ring:\n");
-	xhci_debug_segment(xhci, xhci->cmd_ring->deq_seg);
-	xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
-	xhci_dbg_cmd_ptrs(xhci);
-	for (i = 0; i < MAX_HC_SLOTS; ++i) {
-		if (!xhci->devs[i])
-			continue;
-		for (j = 0; j < 31; ++j) {
-			xhci_dbg_ep_rings(xhci, i, j, &xhci->devs[i]->eps[j]);
-		}
-	}
-	spin_unlock_irqrestore(&xhci->lock, flags);
-
-	if (!xhci->zombie)
-		mod_timer(&xhci->event_ring_timer, jiffies + POLL_TIMEOUT * HZ);
-	else
-		xhci_dbg(xhci, "Quit polling the event ring.\n");
-}
-#endif
-
 static int xhci_run_finished(struct xhci_hcd *xhci)
 {
 	if (xhci_start(xhci)) {
@@ -628,17 +577,6 @@ int xhci_run(struct usb_hcd *hcd)
 	if (ret)
 		return ret;
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-	init_timer(&xhci->event_ring_timer);
-	xhci->event_ring_timer.data = (unsigned long) xhci;
-	xhci->event_ring_timer.function = xhci_event_ring_work;
-	/* Poll the event ring */
-	xhci->event_ring_timer.expires = jiffies + POLL_TIMEOUT * HZ;
-	xhci->zombie = 0;
-	xhci_dbg(xhci, "Setting event ring polling timer\n");
-	add_timer(&xhci->event_ring_timer);
-#endif
-
 	xhci_dbg(xhci, "Command ring memory map follows:\n");
 	xhci_debug_ring(xhci, xhci->cmd_ring);
 	xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
@@ -725,12 +663,6 @@ void xhci_stop(struct usb_hcd *hcd)
 
 	xhci_cleanup_msix(xhci);
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-	/* Tell the event ring poll function not to reschedule */
-	xhci->zombie = 1;
-	del_timer_sync(&xhci->event_ring_timer);
-#endif
-
 	/* Deleting Compliance Mode Recovery Timer */
 	if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
 			(!(xhci_all_ports_seen_u0(xhci)))) {
@@ -1011,12 +943,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 		spin_unlock_irq(&xhci->lock);
 		xhci_cleanup_msix(xhci);
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-		/* Tell the event ring poll function not to reschedule */
-		xhci->zombie = 1;
-		del_timer_sync(&xhci->event_ring_timer);
-#endif
-
 		xhci_dbg(xhci, "// Disabling event ring interrupts\n");
 		temp = xhci_readl(xhci, &xhci->op_regs->status);
 		xhci_writel(xhci, temp & ~STS_EINT, &xhci->op_regs->status);

drivers/usb/host/xhci.h

@@ -1490,11 +1490,6 @@ struct xhci_hcd {
 	struct dma_pool	*small_streams_pool;
 	struct dma_pool	*medium_streams_pool;
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-	/* Poll the rings - for debugging */
-	struct timer_list	event_ring_timer;
-	int			zombie;
-#endif
 	/* Host controller watchdog timer structures */
 	unsigned int		xhc_state;
 
@@ -1579,14 +1574,8 @@ static inline struct usb_hcd *xhci_to_hcd(struct xhci_hcd *xhci)
 	return xhci->main_hcd;
 }
 
-#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-#define XHCI_DEBUG	1
-#else
-#define XHCI_DEBUG	0
-#endif
-
 #define xhci_dbg(xhci, fmt, args...) \
-	do { if (XHCI_DEBUG) dev_dbg(xhci_to_hcd(xhci)->self.controller , fmt , ## args); } while (0)
+	dev_dbg(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 #define xhci_err(xhci, fmt, args...) \
 	dev_err(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 #define xhci_warn(xhci, fmt, args...) \