[U-Boot] [PATCH 1/3] usb: hub: Parallelize power-cycling of root-hub ports
Vivek Gautam
gautam.vivek at samsung.com
Wed Apr 24 14:50:11 CEST 2013
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 at samsung.com>
---
common/usb_hub.c | 23 ++++++++++++++---------
1 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/common/usb_hub.c b/common/usb_hub.c
index 1e225e6..dad0409 100644
--- a/common/usb_hub.c
+++ b/common/usb_hub.c
@@ -105,22 +105,25 @@ 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);
+ printf("port %d: get_port_status failed\n", i + 1);
return;
}
@@ -135,10 +138,12 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
*/
portstatus = le16_to_cpu(portsts->wPortStatus);
if (portstatus & (USB_PORT_STAT_POWER << 1)) {
- debug("port %d: Port power change failed\n", i + 1);
+ printf("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);
}
--
1.7.6.5
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