If the high-speed device does not enter full-speed idle after
wakeup on disconnect logic has effected, there will be an
unexpected disconnect wakeup interrupt due to the bus is still SE0.
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
Hi Alan,
If you can't met this issue, it may due to your hardware enables
WKDN after detecting full-speed idle or the time between stop
SoF and enable WKDN is more than 3ms (You need to know when
the WKDN has really taken effect).
---
Changes for v3:
- Stop SoF first, then delay 3.5-4ms, enable WKDS at last.
Changes for v2:
- Using usleep_range instead of mdelay
drivers/usb/host/ehci-hub.c | 22 +++++++++++++++++++++-
1 files changed, 21 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 47b858f..111ac61 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -300,7 +300,27 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
}
if (t1 != t2) {
- ehci_writel(ehci, t2, reg);
+ /*
+ * If the high-speed device has not switched
+ * to full-speed idle before WKDISC_E has taken
+ * effect, there will be a WKDISC event.
+ */
+ if (t2 & PORT_WKDISC_E &&
+ (ehci_port_speed(ehci, t2)
+ == USB_PORT_STAT_HIGH_SPEED)) {
+ t2 &= ~PORT_WKDISC_E;
+ /* Stop SoF first */
+ ehci_writel(ehci, t2, reg);
+ spin_unlock_irq(&ehci->lock);
+ /* Wait for full-speed idle */
+ usleep_range(3500, 4000);
+ spin_lock_irq(&ehci->lock);
+ t2 |= PORT_WKDISC_E;
+ ehci_writel(ehci, t2, reg);
+ }
+ else {
+ ehci_writel(ehci, t2, reg);
+ }
changed = 1;
}
}
--
1.7.8
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