diff mbox series

[24/24] usb: xhci: bInterval quirk for TI TUSB73x0

Message ID 1491310516-6176-25-git-send-email-mathias.nyman@linux.intel.com
State Superseded
Headers show
Series None | expand

Commit Message

Mathias Nyman April 4, 2017, 12:55 p.m. UTC 
From: Roger Quadros <rogerq@ti.com>


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>

---
 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(+)

-- 
1.9.1

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Comments

Oliver Neukum April 5, 2017, 8:43 a.m. UTC | #1 
Am Dienstag, den 04.04.2017, 15:55 +0300 schrieb Mathias Nyman:
> From: Roger Quadros <rogerq@ti.com>

> 

> 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>


Hi,

this should go into the stable tree.
Could you add a CC?

	Regards
		Oliver

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diff mbox series

Patch

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index b88ec9a..2954b90 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1503,6 +1503,17 @@  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 fc99f51..7b86508 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 dbe8ba9..914968c 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1820,6 +1820,7 @@  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;