From 0bf796f7ae22086f0504f3297e9fb4e96aa04161 Mon Sep 17 00:00:00 2001 From: Vivek Gautam Date: Wed, 24 Apr 2013 02:50:11 +0000 Subject: usb: hub: Parallelize power-cycling of root-hub ports Untill now we power-cycle (aka: disable power on a port and re-enabling again) one port at a time. Delay of 20ms for Port-power to change multiplies with number of ports in this case. So better we parallelize this process: disable power on all ports, wait for port-power to stabilize and then re-enable the power subsequently. Signed-off-by: Vivek Gautam --- common/usb_hub.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'common') diff --git a/common/usb_hub.c b/common/usb_hub.c index 1e225e6b37..4fbfacf249 100644 --- a/common/usb_hub.c +++ b/common/usb_hub.c @@ -105,19 +105,22 @@ static void usb_hub_power_on(struct usb_hub_device *hub) int ret; dev = hub->pusb_dev; - /* Enable power to the ports */ + + /* + * Enable power to the ports: + * Here we Power-cycle the ports: aka, + * turning them off and turning on again. + */ debug("enabling power on all ports\n"); for (i = 0; i < dev->maxchild; i++) { - /* - * Power-cycle the ports here: aka, - * turning them off and turning on again. - */ usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_POWER); debug("port %d returns %lX\n", i + 1, dev->status); + } - /* Wait at least 2*bPwrOn2PwrGood for PP to change */ - mdelay(pgood_delay); + /* Wait at least 2*bPwrOn2PwrGood for PP to change */ + mdelay(pgood_delay); + for (i = 0; i < dev->maxchild; i++) { ret = usb_get_port_status(dev, i + 1, portsts); if (ret < 0) { debug("port %d: get_port_status failed\n", i + 1); @@ -138,7 +141,9 @@ static void usb_hub_power_on(struct usb_hub_device *hub) debug("port %d: Port power change failed\n", i + 1); return; } + } + for (i = 0; i < dev->maxchild; i++) { usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER); debug("port %d returns %lX\n", i + 1, dev->status); } -- cgit v1.2.3