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

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>

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index ba1853f4e407a9558af25e6573ced5a7ec6d01f6..05fb3f65d7f7471cbdec551e5bbebea6e94ac64e 100644 (file)
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1502,6 +1502,17 @@ 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 = 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 fc99f51d12e183603cd692592b6d77351131a1da..7b86508ac8cf522e1143561a6e9a7d8f40f5a964 100644 (file)
--- 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 da3eb695fe5407a6e8fc5dbab8ac5b97a54e32bd..2496bd6304caa6a5820e5dc983c09b777b017e3b 100644 (file)
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1818,6 +1818,7 @@ 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;