[PATCH 4.8 055/138] usb: renesas_usbhs: add wait after initialization for R-Car Gen3

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>

commit b76032396d7958f006bccf5fb2535beb5526837c upstream.

Since the controller on R-Car Gen3 doesn't have any status registers
to detect initialization (LPSTS.SUSPM = 1) and the initialization needs
up to 45 usec, this patch adds wait after the initialization. Otherwise,
writing other registers (e.g. INTENB0) will fail.

Fixes: de18757e272d ("usb: renesas_usbhs: add R-Car Gen3 power control")
Cc: <balbi@xxxxxxxxxx>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/renesas_usbhs/rcar3.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/usb/renesas_usbhs/rcar3.c
+++ b/drivers/usb/renesas_usbhs/rcar3.c
@@ -9,6 +9,7 @@
  *
  */
 
+#include <linux/delay.h>
 #include <linux/io.h>
 #include "common.h"
 #include "rcar3.h"
@@ -35,10 +36,13 @@ static int usbhs_rcar3_power_ctrl(struct
 
 	usbhs_write32(priv, UGCTRL2, UGCTRL2_RESERVED_3 | UGCTRL2_USB0SEL_OTG);
 
-	if (enable)
+	if (enable) {
 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, LPSTS_SUSPM);
-	else
+		/* The controller on R-Car Gen3 needs to wait up to 45 usec */
+		udelay(45);
+	} else {
 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, 0);
+	}
 
 	return 0;
 }