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usb: hub: Parallelize power-cycling of root-hub ports

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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 <gautam.vivek@samsung.com>
This commit is contained in:
Vivek Gautam 2013-04-24 02:50:11 +00:00 committed by Marek Vasut
parent 158947d276
commit 0bf796f7ae
1 changed files with 12 additions and 7 deletions
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19
common/usb_hub.c
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@ -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);
}