[RFC PATCH v3 6/6] usb.c: Add a retry in the usb_prepare_device()

[Jason Wessel]

I have found through testing some USB 2 composite mouse/keyboard
devices do not response to the usb_set_address call immediately
following the port reset.  It can take anywhere from 2ms to 20ms.

This patch adds a retry and delay for usb_prepare_device() and allows
all the USB keyboards I tried to function properly.

Signed-off-by: Jason Wessel <jason.wessel at windriver.com>
---
 common/usb.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/common/usb.c b/common/usb.c
index ba83bb960b..fb091440cc 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -1054,6 +1054,15 @@ static int usb_prepare_device(struct usb_device *dev, int addr, bool do_read,
 	dev->devnum = addr;
 
 	err = usb_set_address(dev); /* set address */
+	/* Retry for old composite keyboard/mouse usb2 hardware */
+	int i = 0;
+	while (err < 0 && i <= 40) {
+		i += 20;
+		mdelay(20);
+		err = usb_set_address(dev); /* set address */
+	}
+	if (i > 0)
+		debug("usb_set_address delay: %i\n", i);
 	if (err < 0)
 		debug("\n       usb_set_address return < 0\n");
 	if (err < 0 && dev->status != 0) {
-- 
2.17.1