Merge tag 'qcom-soc-for-3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / drivers / usb / phy / phy-am335x-control.c

diff --git a/drivers/usb/phy/phy-am335x-control.c b/drivers/usb/phy/phy-am335x-control.c
index d75196a..35b6083 100644 (file)
--- a/drivers/usb/phy/phy-am335x-control.c
+++ b/drivers/usb/phy/phy-am335x-control.c
@@ -3,6 +3,7 @@
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/io.h>
+#include <linux/delay.h>
 #include "am35x-phy-control.h"
 
 struct am335x_control_usb {
@@ -86,6 +87,14 @@ static void am335x_phy_power(struct phy_control *phy_ctrl, u32 id, bool on)
        }
 
        writel(val, usb_ctrl->phy_reg + reg);
+
+       /*
+        * Give the PHY ~1ms to complete the power up operation.
+        * Tests have shown unstable behaviour if other USB PHY related
+        * registers are written too shortly after such a transition.
+        */
+       if (on)
+               mdelay(1);
 }
 
 static const struct phy_control ctrl_am335x = {