Patch "usb: xhci: bInterval quirk for TI TUSB73x0" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    usb: xhci: bInterval quirk for TI TUSB73x0

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-xhci-binterval-quirk-for-ti-tusb73x0.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 69307ccb9ad7ccb653e332de68effdeaaab6907d Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq@ti.com>
Date: Fri, 7 Apr 2017 17:57:12 +0300
Subject: usb: xhci: bInterval quirk for TI TUSB73x0

From: Roger Quadros <rogerq@ti.com>

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

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>

---
 drivers/usb/host/xhci-mem.c |   11 +++++++++++
 drivers/usb/host/xhci-pci.c |    3 +++
 drivers/usb/host/xhci.h     |    1 +
 3 files changed, 15 insertions(+)

--- 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 *
 	 */
 	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);
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -199,6 +199,9 @@ static void xhci_pci_quirks(struct devic
 			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");
--- 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;


Patches currently in stable-queue which might be from rogerq@ti.com are

queue-4.9/usb-xhci-binterval-quirk-for-ti-tusb73x0.patch