Resolve synchronization issue between host
and gadget drivers upon role-reversal.

Signed-off-by: Ramneek Mehresh <ramneek.mehr...@freescale.com>
Reviewed-by: Li Yang-R58472 <le...@freescale.com>
Reviewed-by: Fleming Andrew-AFLEMING <aflem...@freescale.com>
Tested-by: Fleming Andrew-AFLEMING <aflem...@freescale.com>
---
 drivers/usb/phy/phy-fsl-usb.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/phy/phy-fsl-usb.c b/drivers/usb/phy/phy-fsl-usb.c
index 689516d..5d678ea 100644
--- a/drivers/usb/phy/phy-fsl-usb.c
+++ b/drivers/usb/phy/phy-fsl-usb.c
@@ -544,8 +544,18 @@ int fsl_otg_start_gadget(struct otg_fsm *fsm, int on)
        dev = otg->gadget->dev.parent;
 
        if (on) {
-               if (dev->driver->resume)
+               /*
+                * Delay gadget resume to synchronize between host and gadget
+                * drivers. Upon role-reversal host drv is shutdown by kernel
+                * worker thread. By the time host drv shuts down, controller
+                * gets programmed for gadget role. Shutting host drv after
+                * this results in controller getting reset, and it stops
+                * responding to otg events
+                */
+               if (dev->driver->resume) {
+                       msleep(1000);
                        dev->driver->resume(dev);
+               }
        } else {
                if (dev->driver->suspend)
                        dev->driver->suspend(dev, otg_suspend_state);
-- 
1.8.3.1

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