USB: xhci: Make debugging more verbose.

Add more debugging to the irq handler, slot context initialization, ring
operations, URB cancellation, and MMIO writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/xhci-hcd.c

@@ -267,8 +267,10 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	u32 temp, temp2;
+	union xhci_trb *trb;
 
 	spin_lock(&xhci->lock);
+	trb = xhci->event_ring->dequeue;
 	/* Check if the xHC generated the interrupt, or the irq is shared */
 	temp = xhci_readl(xhci, &xhci->op_regs->status);
 	temp2 = xhci_readl(xhci, &xhci->ir_set->irq_pending);
@@ -276,6 +278,15 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 		spin_unlock(&xhci->lock);
 		return IRQ_NONE;
 	}
+	xhci_dbg(xhci, "op reg status = %08x\n", temp);
+	xhci_dbg(xhci, "ir set irq_pending = %08x\n", temp2);
+	xhci_dbg(xhci, "Event ring dequeue ptr:\n");
+	xhci_dbg(xhci, "@%llx %08x %08x %08x %08x\n",
+			(unsigned long long)xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, trb),
+			lower_32_bits(trb->link.segment_ptr),
+			upper_32_bits(trb->link.segment_ptr),
+			(unsigned int) trb->link.intr_target,
+			(unsigned int) trb->link.control);
 
 	if (temp & STS_FATAL) {
 		xhci_warn(xhci, "WARNING: Host System Error\n");
@@ -385,6 +396,20 @@ int xhci_run(struct usb_hcd *hcd)
 	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);
+	xhci_dbg_cmd_ptrs(xhci);
+
+	xhci_dbg(xhci, "ERST memory map follows:\n");
+	xhci_dbg_erst(xhci, &xhci->erst);
+	xhci_dbg(xhci, "Event ring:\n");
+	xhci_debug_ring(xhci, xhci->event_ring);
+	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, "// Set the interrupt modulation register\n");
 	temp = xhci_readl(xhci, &xhci->ir_set->irq_control);
 	temp &= ~ER_IRQ_INTERVAL_MASK;
@@ -409,20 +434,6 @@ int xhci_run(struct usb_hcd *hcd)
 	if (NUM_TEST_NOOPS > 0)
 		doorbell = xhci_setup_one_noop(xhci);
 
-	xhci_dbg(xhci, "Command ring memory map follows:\n");
-	xhci_debug_ring(xhci, xhci->cmd_ring);
-	xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
-	xhci_dbg_cmd_ptrs(xhci);
-
-	xhci_dbg(xhci, "ERST memory map follows:\n");
-	xhci_dbg_erst(xhci, &xhci->erst);
-	xhci_dbg(xhci, "Event ring:\n");
-	xhci_debug_ring(xhci, xhci->event_ring);
-	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);
-
 	temp = xhci_readl(xhci, &xhci->op_regs->command);
 	temp |= (CMD_RUN);
 	xhci_dbg(xhci, "// Turn on HC, cmd = 0x%x.\n",
@@ -665,8 +676,12 @@ int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 		goto done;
 
 	xhci_dbg(xhci, "Cancel URB %p\n", urb);
+	xhci_dbg(xhci, "Event ring:\n");
+	xhci_debug_ring(xhci, xhci->event_ring);
 	ep_index = xhci_get_endpoint_index(&urb->ep->desc);
 	ep_ring = xhci->devs[urb->dev->slot_id]->ep_rings[ep_index];
+	xhci_dbg(xhci, "Endpoint ring:\n");
+	xhci_debug_ring(xhci, ep_ring);
 	td = (struct xhci_td *) urb->hcpriv;
 
 	ep_ring->cancels_pending++;
@@ -1178,6 +1193,8 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 	if (!udev->config)
 		xhci_setup_addressable_virt_dev(xhci, udev);
 	/* Otherwise, assume the core has the device configured how it wants */
+	xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
+	xhci_dbg_ctx(xhci, virt_dev->in_ctx, virt_dev->in_ctx_dma, 2);
 
 	spin_lock_irqsave(&xhci->lock, flags);
 	ret = xhci_queue_address_device(xhci, virt_dev->in_ctx_dma,
@@ -1221,6 +1238,8 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 	default:
 		xhci_err(xhci, "ERROR: unexpected command completion "
 				"code 0x%x.\n", virt_dev->cmd_status);
+		xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
+		xhci_dbg_ctx(xhci, virt_dev->out_ctx, virt_dev->out_ctx_dma, 2);
 		ret = -EINVAL;
 		break;
 	}

drivers/usb/host/xhci-ring.c

@@ -135,6 +135,7 @@ static void next_trb(struct xhci_hcd *xhci,
 static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
 {
 	union xhci_trb *next = ++(ring->dequeue);
+	unsigned long long addr;
 
 	ring->deq_updates++;
 	/* Update the dequeue pointer further if that was a link TRB or we're at
@@ -152,6 +153,13 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
 		ring->dequeue = ring->deq_seg->trbs;
 		next = ring->dequeue;
 	}
+	addr = (unsigned long long) xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
+	if (ring == xhci->event_ring)
+		xhci_dbg(xhci, "Event ring deq = 0x%llx (DMA)\n", addr);
+	else if (ring == xhci->cmd_ring)
+		xhci_dbg(xhci, "Command ring deq = 0x%llx (DMA)\n", addr);
+	else
+		xhci_dbg(xhci, "Ring deq = 0x%llx (DMA)\n", addr);
 }
 
 /*
@@ -171,6 +179,7 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
 {
 	u32 chain;
 	union xhci_trb *next;
+	unsigned long long addr;
 
 	chain = ring->enqueue->generic.field[3] & TRB_CHAIN;
 	next = ++(ring->enqueue);
@@ -204,6 +213,13 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
 		ring->enqueue = ring->enq_seg->trbs;
 		next = ring->enqueue;
 	}
+	addr = (unsigned long long) xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
+	if (ring == xhci->event_ring)
+		xhci_dbg(xhci, "Event ring enq = 0x%llx (DMA)\n", addr);
+	else if (ring == xhci->cmd_ring)
+		xhci_dbg(xhci, "Command ring enq = 0x%llx (DMA)\n", addr);
+	else
+		xhci_dbg(xhci, "Ring enq = 0x%llx (DMA)\n", addr);
 }
 
 /*
@@ -252,7 +268,6 @@ void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
 	 * there might be more events to service.
 	 */
 	temp &= ~ERST_EHB;
-	if (!in_interrupt())
 	xhci_dbg(xhci, "// Write event ring dequeue pointer, preserving EHB bit\n");
 	xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp,
 			&xhci->ir_set->erst_dequeue);
@@ -781,6 +796,7 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 	struct urb *urb = 0;
 	int status = -EINPROGRESS;
 
+	xhci_dbg(xhci, "In %s\n", __func__);
 	xdev = xhci->devs[TRB_TO_SLOT_ID(event->flags)];
 	if (!xdev) {
 		xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
@@ -789,6 +805,7 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 
 	/* Endpoint ID is 1 based, our index is zero based */
 	ep_index = TRB_TO_EP_ID(event->flags) - 1;
+	xhci_dbg(xhci, "%s - ep index = %d\n", __func__, ep_index);
 	ep_ring = xdev->ep_rings[ep_index];
 	if (!ep_ring || (xdev->out_ctx->ep[ep_index].ep_info & EP_STATE_MASK) == EP_STATE_DISABLED) {
 		xhci_err(xhci, "ERROR Transfer event pointed to disabled endpoint\n");
@@ -797,6 +814,7 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 
 	event_dma = event->buffer;
 	/* This TRB should be in the TD at the head of this ring's TD list */
+	xhci_dbg(xhci, "%s - checking for list empty\n", __func__);
 	if (list_empty(&ep_ring->td_list)) {
 		xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
 				TRB_TO_SLOT_ID(event->flags), ep_index);
@@ -806,11 +824,14 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 		urb = NULL;
 		goto cleanup;
 	}
+	xhci_dbg(xhci, "%s - getting list entry\n", __func__);
 	td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
 
 	/* Is this a TRB in the currently executing TD? */
+	xhci_dbg(xhci, "%s - looking for TD\n", __func__);
 	event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
 			td->last_trb, event_dma);
+	xhci_dbg(xhci, "%s - found event_seg = %p\n", __func__, event_seg);
 	if (!event_seg) {
 		/* HC is busted, give up! */
 		xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not part of current TD\n");
@@ -1027,6 +1048,8 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 	/* FIXME for multi-TD URBs (who have buffers bigger than 64MB) */
 	if (urb) {
 		usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
+		xhci_dbg(xhci, "Giveback URB %p, len = %d, status = %d\n",
+				urb, td->urb->actual_length, status);
 		spin_unlock(&xhci->lock);
 		usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
 		spin_lock(&xhci->lock);
@@ -1044,6 +1067,7 @@ void xhci_handle_event(struct xhci_hcd *xhci)
 	int update_ptrs = 1;
 	int ret;
 
+	xhci_dbg(xhci, "In %s\n", __func__);
 	if (!xhci->event_ring || !xhci->event_ring->dequeue) {
 		xhci->error_bitmask |= 1 << 1;
 		return;
@@ -1056,18 +1080,25 @@ void xhci_handle_event(struct xhci_hcd *xhci)
 		xhci->error_bitmask |= 1 << 2;
 		return;
 	}
+	xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
 
 	/* FIXME: Handle more event types. */
 	switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
 	case TRB_TYPE(TRB_COMPLETION):
+		xhci_dbg(xhci, "%s - calling handle_cmd_completion\n", __func__);
 		handle_cmd_completion(xhci, &event->event_cmd);
+		xhci_dbg(xhci, "%s - returned from handle_cmd_completion\n", __func__);
 		break;
 	case TRB_TYPE(TRB_PORT_STATUS):
+		xhci_dbg(xhci, "%s - calling handle_port_status\n", __func__);
 		handle_port_status(xhci, event);
+		xhci_dbg(xhci, "%s - returned from handle_port_status\n", __func__);
 		update_ptrs = 0;
 		break;
 	case TRB_TYPE(TRB_TRANSFER):
+		xhci_dbg(xhci, "%s - calling handle_tx_event\n", __func__);
 		ret = handle_tx_event(xhci, &event->trans_event);
+		xhci_dbg(xhci, "%s - returned from handle_tx_event\n", __func__);
 		if (ret < 0)
 			xhci->error_bitmask |= 1 << 9;
 		else

drivers/usb/host/xhci.h

@@ -1065,7 +1065,6 @@ static inline unsigned int xhci_readl(const struct xhci_hcd *xhci,
 static inline void xhci_writel(struct xhci_hcd *xhci,
 		const unsigned int val, __u32 __iomem *regs)
 {
-	if (!in_interrupt())
 	xhci_dbg(xhci,
 			"`MEM_WRITE_DWORD(3'b000, 32'h%p, 32'h%0x, 4'hf);\n",
 			regs, val);
@@ -1096,7 +1095,6 @@ static inline void xhci_write_64(struct xhci_hcd *xhci,
 	u32 val_lo = lower_32_bits(val);
 	u32 val_hi = upper_32_bits(val);
 
-	if (!in_interrupt())
 	xhci_dbg(xhci,
 			"`MEM_WRITE_DWORD(3'b000, 64'h%p, 64'h%0lx, 4'hf);\n",
 			regs, (long unsigned int) val);