USB: EHCI: Ensure 10 msec delay between bus states
According to EHCI specification, software must wait for at least 10 msec
after a port indicates that it is suspended before initiating a port
resume. The current code uses jiffies and fails to give the delay if
suspend and resume happens at the timer tick boundaries.
The correct implementation would be ensuring this delay by using hrtimers
or ktime_get(). This involves changing many drivers. Hence workaround
it by increasing the state change delay to 2 jiffies.
CRs-Fixed: 521047
Change-Id: I703210cca83d649d1b253e971dfba8f62c6ccb8c
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index cfdb688..59ab07b 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -210,8 +210,8 @@
ehci_dbg(ehci, "suspend root hub\n");
- if (time_before (jiffies, ehci->next_statechange))
- msleep(5);
+ if (time_before_eq(jiffies, ehci->next_statechange))
+ usleep_range(10000, 10000);
del_timer_sync(&ehci->watchdog);
del_timer_sync(&ehci->iaa_watchdog);
@@ -345,8 +345,8 @@
int i;
unsigned long resume_needed = 0;
- if (time_before (jiffies, ehci->next_statechange))
- msleep(5);
+ if (time_before_eq(jiffies, ehci->next_statechange))
+ usleep_range(10000, 10000);
spin_lock_irq (&ehci->lock);
if (!HCD_HW_ACCESSIBLE(hcd)) {
spin_unlock_irq(&ehci->lock);