Commit 41135de1 authored Jan 23, 2017 by Felipe Balbi Committed by Greg Kroah-Hartman Jan 25, 2017

usb: xhci: add quirk flag for broken PED bits

Some devices from Texas Instruments [1] suffer from
a silicon bug where Port Enabled/Disabled bit
should not be used to silence an erroneous device.

The bug is so that if port is disabled with PED
bit, an IRQ for device removal (or attachment)
will never fire.

Just for the sake of completeness, the actual
problem lies with SNPS USB IP and this affects
all known versions up to 3.00a. A separate
patch will be added to dwc3 to enabled this
quirk flag if version is <= 3.00a.

[1] - AM572x Silicon Errata http://www.ti.com/lit/er/sprz429j/sprz429j.pdf


Section i896— USB xHCI Port Disable Feature Does Not Work

Signed-off-by: Felipe Balbi <balbi@ti.com>
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>

parent 52c31bd5

drivers/usb/host/xhci-hub.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -458,6 +458,12 @@ static void xhci_disable_port(struct usb_hcd hcd, struct xhci_hcd xhci,
		return;
		}

		if (xhci->quirks & XHCI_BROKEN_PORT_PED) {
		xhci_dbg(xhci,
		"Broken Port Enabled/Disabled, ignoring port disable request.\n");
		return;
		}

		/* Write 1 to disable the port */
		writel(port_status \| PORT_PE, addr);
		port_status = readl(addr);

drivers/usb/host/xhci.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -1648,6 +1648,9 @@ struct xhci_hcd {
		#define XHCI_SSIC_PORT_UNUSED (1 << 22)
		#define XHCI_NO_64BIT_SUPPORT (1 << 23)
		#define XHCI_MISSING_CAS (1 << 24)
		/* For controller with a broken Port Disable implementation */
		#define XHCI_BROKEN_PORT_PED (1 << 25)

		unsigned int num_active_eps;
		unsigned int limit_active_eps;
		/* There are two roothubs to keep track of bus suspend info for */

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