@@ -224,6 +224,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
int port;
int mask;
int changed;
+ bool fs_idle_delay;
ehci_dbg(ehci, "suspend root hub\n");
@@ -258,6 +259,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
ehci->bus_suspended = 0;
ehci->owned_ports = 0;
changed = 0;
+ fs_idle_delay = false;
port = HCS_N_PORTS(ehci->hcs_params);
while (port--) {
u32 __iomem *reg = &ehci->regs->port_status [port];
@@ -288,16 +290,32 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
if (t1 != t2) {
ehci_vdbg (ehci, "port %d, %08x -> %08x\n",
port + 1, t1, t2);
+ /*
+ * On some controllers, Wake-On-Disconnect will
+ * generate false wakeup signals until the bus
+ * switches over to full-speed idle. For their
+ * sake, add a delay if we need one.
+ */
+ if ((t2 & PORT_WKDISC_E) &&
+ ehci_port_speed(ehci, t2) ==
+ USB_PORT_STAT_HIGH_SPEED)
+ fs_idle_delay = true;
ehci_writel(ehci, t2, reg);
changed = 1;
}
}
+ spin_unlock_irq(&ehci->lock);
+
+ if ((changed && ehci->has_hostpc) || fs_idle_delay) {
+ /*
+ * Wait for HCD to enter low-power mode or for the bus
+ * to switch to full-speed idle.
+ */
+ usleep_range(5000, 5500);
+ }
if (changed && ehci->has_hostpc) {
- spin_unlock_irq(&ehci->lock);
- msleep(5); /* 5 ms for HCD to enter low-power mode */
spin_lock_irq(&ehci->lock);
-
port = HCS_N_PORTS(ehci->hcs_params);
while (port--) {
u32 __iomem *hostpc_reg = &ehci->regs->hostpc[port];
@@ -310,8 +328,8 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
port, (t3 & HOSTPC_PHCD) ?
"succeeded" : "failed");
}
+ spin_unlock_irq(&ehci->lock);
}
- spin_unlock_irq(&ehci->lock);
/* Apparently some devices need a >= 1-uframe delay here */
if (ehci->bus_suspended)
This is a note to let you know that I have just added a patch titled USB: EHCI: add delay during suspend to prevent erroneous wakeups to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.20. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From fa2ee1b986507b20552ea87169b056cab2f5d9b2 Mon Sep 17 00:00:00 2001 From: Alan Stern <stern@rowland.harvard.edu> Date: Thu, 13 Feb 2014 15:49:17 -0500 Subject: USB: EHCI: add delay during suspend to prevent erroneous wakeups commit 3e8d6d85adedc59115a564c0a54b36e42087c4d9 upstream. High-speed USB connections revert back to full-speed signalling when the device goes into suspend. This takes several milliseconds, and during that time it's not possible to tell reliably whether the device has been disconnected. On some platforms, the Wake-On-Disconnect circuitry gets confused during this intermediate state. It generates a false wakeup signal, which can prevent the controller from going to sleep. To avoid this problem, this patch adds a 5-ms delay to the ehci_bus_suspend() routine if any ports have to switch over to full-speed signalling. (Actually, the delay was already present for devices using a particular kind of PHY power management; the patch merely causes the delay to be used more widely.) Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reviewed-by: Peter Chen <Peter.Chen@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [ kamal: backport to 3.8 (context) ] Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/usb/host/ehci-hub.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) -- 1.8.3.2