usb: hub: allow pgood_delay to be specified via env

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

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
This commit is contained in:
Tim Harvey 2015-04-08 12:21:12 -07:00 committed by Marek Vasut
parent 25c0673635
commit 319418c01c

View file

@ -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 +99,14 @@ 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,
(unsigned)simple_strtol(env, NULL, 0));
debug("pgood_delay=%dms\n", pgood_delay);
mdelay(pgood_delay + 1000);
}