release/4.8.26/usb-xhci-bInterval-quirk-for-TI-TUSB73x0.patch

From 885e7a6e3263fabfc9e5c0a39fad276d9ed4c798 Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq@ti.com>
Date: Fri, 7 Apr 2017 17:57:12 +0300
Subject: [PATCH] usb: xhci: bInterval quirk for TI TUSB73x0

commit 69307ccb9ad7ccb653e332de68effdeaaab6907d upstream.

As per [1] issue #4,
"The periodic EP scheduler always tries to schedule the EPs
that have large intervals (interval equal to or greater than
128 microframes) into different microframes. So it maintains
an internal counter and increments for each large interval
EP added. When the counter is greater than 128, the scheduler
rejects the new EP. So when the hub re-enumerated 128 times,
it triggers this condition."

This results in Bandwidth error when devices with periodic
endpoints (ISO/INT) having bInterval > 7 are plugged and
unplugged several times on a TUSB73x0 XHCI host.

Workaround this issue by limiting the bInterval to 7
(i.e. interval to 6) for High-speed or faster periodic endpoints.

[1] - http://www.ti.com/lit/er/sllz076/sllz076.pdf

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 7064892ff4a6..87848ce95b6f 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1494,6 +1494,17 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	 */
 	max_esit_payload = xhci_get_max_esit_payload(udev, ep);
 	interval = xhci_get_endpoint_interval(udev, ep);
+
+	/* Periodic endpoint bInterval limit quirk */
+	if (usb_endpoint_xfer_int(&ep->desc) ||
+	    usb_endpoint_xfer_isoc(&ep->desc)) {
+		if ((xhci->quirks & XHCI_LIMIT_ENDPOINT_INTERVAL_7) &&
+		    udev->speed >= USB_SPEED_HIGH &&
+		    interval >= 7) {
+			interval = 6;
+		}
+	}
+
 	mult = xhci_get_endpoint_mult(udev, ep);
 	max_packet = GET_MAX_PACKET(usb_endpoint_maxp(&ep->desc));
 	max_burst = xhci_get_endpoint_max_burst(udev, ep);
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 954abfd5014d..93f566cb968b 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -199,6 +199,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 			pdev->device == 0x1042)
 		xhci->quirks |= XHCI_BROKEN_STREAMS;
 
+	if (pdev->vendor == PCI_VENDOR_ID_TI && pdev->device == 0x8241)
+		xhci->quirks |= XHCI_LIMIT_ENDPOINT_INTERVAL_7;
+
 	if (xhci->quirks & XHCI_RESET_ON_RESUME)
 		xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
 				"QUIRK: Resetting on resume");
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index f97b009ffc40..328fe06752ec 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1659,6 +1659,7 @@ struct xhci_hcd {
 #define XHCI_MISSING_CAS	(1 << 24)
 /* For controller with a broken Port Disable implementation */
 #define XHCI_BROKEN_PORT_PED	(1 << 25)
+#define XHCI_LIMIT_ENDPOINT_INTERVAL_7	(1 << 26)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.12.0