From a1a28c6e64b9a6b0b911d066c627bc77f52179fb Mon Sep 17 00:00:00 2001 From: Wolfgang Grandegger Date: Wed, 21 Dec 2011 00:01:09 +0000 Subject: [PATCH] USB: relax usbcore reset timings Following the corresponding Linux code, this patch relaxes reset timings waiting at least 100ms after power to the ports. There are some reports that it helps make enumeration work better on some high speed devices. Furthermore, the wait is only done once after power has been enabled on all ports. CC: Remy Bohmer CC: Vincent Palatin Signed-off-by: Wolfgang Grandegger --- common/usb_hub.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/common/usb_hub.c b/common/usb_hub.c index 576e0e6a93..84d0d3f9c1 100644 --- a/common/usb_hub.c +++ b/common/usb_hub.c @@ -109,6 +109,7 @@ static void usb_hub_power_on(struct usb_hub_device *hub) { int i; struct usb_device *dev; + unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2; dev = hub->pusb_dev; /* Enable power to the ports */ @@ -116,8 +117,10 @@ static void usb_hub_power_on(struct usb_hub_device *hub) for (i = 0; i < dev->maxchild; i++) { usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER); USB_HUB_PRINTF("port %d returns %lX\n", i + 1, dev->status); - wait_ms(hub->desc.bPwrOn2PwrGood * 2); } + + /* Wait at least 100 msec for power to become stable */ + wait_ms(max(pgood_delay, (unsigned)100)); } void usb_hub_reset(void) -- 2.39.5