[PATCH v2] [RFC] USB: hub.c: decrease the number of attempts of enumeration scheme

[Yasushi Asano <yazzep@gmail.com>]

From: Yasushi Asano <yasano@jp.adit-jv.com>

According to 6.7.22 A-UUT “Device No Response” for connection timeout
of USB OTG and EH automated compliance plan v1.2, the enumeration
failure has to be detected within 30 seconds. However, the old and new
enumeration schemes made a total of 16 attempts, and each attempt can
take 5 seconds to timeout, so it failed with PET test. Modify it to
reduce the number of attempts to 5 and pass PET test.

in case of old_schene_first=N and use_both_schemes=Y
attempt 3 * new scheme, then 2 * old scheme
in case of old_schene_first=Y and use_both_schemes=Y
attempt 2 * old scheme, then 3 * new scheme

Signed-off-by: Yasushi Asano <yasano@jp.adit-jv.com>
---
 drivers/usb/core/hub.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 052d5ac..5b15278c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2706,7 +2706,6 @@ static unsigned hub_is_wusb(struct usb_hub *hub)
 
 
 #define PORT_RESET_TRIES	5
-#define SET_ADDRESS_TRIES	2
 #define GET_DESCRIPTOR_TRIES	2
 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
 #define USE_NEW_SCHEME(i, scheme)	((i) / 2 == (int)(scheme))
@@ -4539,7 +4538,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 	struct usb_device	*hdev = hub->hdev;
 	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
 	struct usb_port		*port_dev = hub->ports[port1 - 1];
-	int			retries, operations, retval, i;
+	int			retries, retval, i;
 	unsigned		delay = HUB_SHORT_RESET_TIME;
 	enum usb_device_speed	oldspeed = udev->speed;
 	const char		*speed;
@@ -4684,7 +4683,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 			 * 255 is for WUSB devices, we actually need to use
 			 * 512 (WUSB1.0[4.8.1]).
 			 */
-			for (operations = 0; operations < 3; ++operations) {
+			if (!((retry_counter % 2 != 0) && (retries != 0))) {
 				buf->bMaxPacketSize0 = 0;
 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
@@ -4714,7 +4713,10 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 						retries == 0 &&
 						udev->speed > USB_SPEED_FULL))
 					break;
+			} else {
+				break;
 			}
+
 			udev->descriptor.bMaxPacketSize0 =
 					buf->bMaxPacketSize0;
 			kfree(buf);
@@ -4744,12 +4746,8 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 		 * authorization will assign the final address.
 		 */
 		if (udev->wusb == 0) {
-			for (operations = 0; operations < SET_ADDRESS_TRIES; ++operations) {
-				retval = hub_set_address(udev, devnum);
-				if (retval >= 0)
-					break;
-				msleep(200);
-			}
+			retval = hub_set_address(udev, devnum);
+			msleep(200);
 			if (retval < 0) {
 				if (retval != -ENODEV)
 					dev_err(&udev->dev, "device not accepting address %d, error %d\n",
-- 
2.7.4