4 files changed, 57 insertions, 5 deletions

diff --git a/drivers/usb/host/ehci-mem.c b/drivers/usb/host/ehci-mem.c
index d36e4e75e08d..12f70c302b0b 100644
--- a/drivers/usb/host/ehci-mem.c
+++ b/drivers/usb/host/ehci-mem.c
@@ -141,6 +141,10 @@ static void ehci_mem_cleanup (struct ehci_hcd *ehci)
 		qh_put (ehci->async);
 	ehci->async = NULL;
 
+	if (ehci->dummy)
+		qh_put(ehci->dummy);
+	ehci->dummy = NULL;
+
 	/* DMA consistent memory and pools */
 	if (ehci->qtd_pool)
 		dma_pool_destroy (ehci->qtd_pool);
@@ -227,8 +231,26 @@ static int ehci_mem_init (struct ehci_hcd *ehci, gfp_t flags)
 	if (ehci->periodic == NULL) {
 		goto fail;
 	}
-	for (i = 0; i < ehci->periodic_size; i++)
-		ehci->periodic [i] = EHCI_LIST_END(ehci);
+
+	if (ehci->use_dummy_qh) {
+		struct ehci_qh_hw	*hw;
+		ehci->dummy = ehci_qh_alloc(ehci, flags);
+		if (!ehci->dummy)
+			goto fail;
+
+		hw = ehci->dummy->hw;
+		hw->hw_next = EHCI_LIST_END(ehci);
+		hw->hw_qtd_next = EHCI_LIST_END(ehci);
+		hw->hw_alt_next = EHCI_LIST_END(ehci);
+		hw->hw_token &= ~QTD_STS_ACTIVE;
+		ehci->dummy->hw = hw;
+
+		for (i = 0; i < ehci->periodic_size; i++)
+			ehci->periodic[i] = ehci->dummy->qh_dma;
+	} else {
+		for (i = 0; i < ehci->periodic_size; i++)
+			ehci->periodic[i] = EHCI_LIST_END(ehci);
+	}
 
 	/* software shadow of hardware table */
 	ehci->pshadow = kcalloc(ehci->periodic_size, sizeof(void *), flags);
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index a1e8d273103f..01bb72b71832 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -103,6 +103,19 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
 	if (retval)
 		return retval;
 
+	if ((pdev->vendor == PCI_VENDOR_ID_AMD && pdev->device == 0x7808) ||
+	    (pdev->vendor == PCI_VENDOR_ID_ATI && pdev->device == 0x4396)) {
+		/* EHCI controller on AMD SB700/SB800/Hudson-2/3 platforms may
+		 * read/write memory space which does not belong to it when
+		 * there is NULL pointer with T-bit set to 1 in the frame list
+		 * table. To avoid the issue, the frame list link pointer
+		 * should always contain a valid pointer to a inactive qh.
+		 */
+		ehci->use_dummy_qh = 1;
+		ehci_info(ehci, "applying AMD SB700/SB800/Hudson-2/3 EHCI "
+				"dummy qh workaround\n");
+	}
+
 	/* data structure init */
 	retval = ehci_init(hcd);
 	if (retval)
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index a92526d6e5ae..d9f78eb26572 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -98,7 +98,14 @@ static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
 	 */
 	*prev_p = *periodic_next_shadow(ehci, &here,
 			Q_NEXT_TYPE(ehci, *hw_p));
-	*hw_p = *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p));
+
+	if (!ehci->use_dummy_qh ||
+	    *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p))
+			!= EHCI_LIST_END(ehci))
+		*hw_p = *shadow_next_periodic(ehci, &here,
+				Q_NEXT_TYPE(ehci, *hw_p));
+	else
+		*hw_p = ehci->dummy->qh_dma;
 }
 
 /* how many of the uframe's 125 usecs are allocated? */
@@ -2335,7 +2342,11 @@ restart:
 				 * pointer for much longer, if at all.
 				 */
 				*q_p = q.itd->itd_next;
-				*hw_p = q.itd->hw_next;
+				if (!ehci->use_dummy_qh ||
+				    q.itd->hw_next != EHCI_LIST_END(ehci))
+					*hw_p = q.itd->hw_next;
+				else
+					*hw_p = ehci->dummy->qh_dma;
 				type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
 				wmb();
 				modified = itd_complete (ehci, q.itd);
@@ -2368,7 +2379,11 @@ restart:
 				 * URB completion.
 				 */
 				*q_p = q.sitd->sitd_next;
-				*hw_p = q.sitd->hw_next;
+				if (!ehci->use_dummy_qh ||
+				    q.sitd->hw_next != EHCI_LIST_END(ehci))
+					*hw_p = q.sitd->hw_next;
+				else
+					*hw_p = ehci->dummy->qh_dma;
 				type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
 				wmb();
 				modified = sitd_complete (ehci, q.sitd);
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index bde823f704e9..ba8eab366b82 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -73,6 +73,7 @@ struct ehci_hcd {			/* one per controller */
 
 	/* async schedule support */
 	struct ehci_qh		*async;
+	struct ehci_qh		*dummy;		/* For AMD quirk use */
 	struct ehci_qh		*reclaim;
 	unsigned		scanning : 1;
 
@@ -131,6 +132,7 @@ struct ehci_hcd {			/* one per controller */
 	unsigned		need_io_watchdog:1;
 	unsigned		broken_periodic:1;
 	unsigned		fs_i_thresh:1;	/* Intel iso scheduling */
+	unsigned		use_dummy_qh:1;	/* AMD Frame List table quirk*/
 
 	/* required for usb32 quirk */
 	#define OHCI_CTRL_HCFS          (3 << 6)