[U-Boot] [PATCH] usb: hub: allow pgood_delay to be specified via env

[Tim Harvey]

Some USB devices break the spec and require longer warm-up times. Allow
the usb_pgood_delay env variable to override the calculated time.

I have encountered this specficically with several different sized/branded USB
sticks with VID:PID 058f:6387 (Alcor Micro Corp. Transcend JetFlash) where I
need to set usb_pgood_delay to 2000ms to make them detectable.

Signed-off-by: Tim Harvey <tharvey at gateworks.com>
---
 common/usb_hub.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/common/usb_hub.c b/common/usb_hub.c
index 66b4a72..a0ef058 100644
--- a/common/usb_hub.c
+++ b/common/usb_hub.c
@@ -86,6 +86,7 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
 	int i;
 	struct usb_device *dev;
 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
+	const char *env;
 
 	dev = hub->pusb_dev;
 
@@ -98,7 +99,13 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
 	/*
 	 * Wait for power to become stable,
 	 * plus spec-defined max time for device to connect
+	 * but allow this time to be increased via env variable as some
+	 * devices break the spec and require longer warm-up times
 	 */
+	env = getenv("usb_pgood_delay");
+	if (env)
+		pgood_delay = max(pgood_delay, simple_strtol(env, NULL, 0));
+	debug("pgood_delay=%dms\n", pgood_delay);
 	mdelay(pgood_delay + 1000);
 }
 
-- 
1.9.1