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usb: Remove 200 ms delay in usb_hub_port_connect_change() 

This patch removes 2 mdelay(200) calls from usb_hub_port_connect_change().
These delays don't seem to be necessary. At least not in my tests. Here
the number for a custom x86 Bay Trail board (not in mainline yet) with
a quite large and complex USB hub infrastructure.

Without this patch:
starting USB...
USB0:   USB EHCI 1.00
scanning bus 0 for devices... 9 USB Device(s) found

time: 28.415 seconds

With this patch:
starting USB...
USB0:   USB EHCI 1.00
scanning bus 0 for devices... 9 USB Device(s) found

time: 24.003 seconds

So ~4.5 seconds of USB scanning time reduction.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Cc: Marek Vasut <marex@denx.de>
This commit is contained in:
Stefan Roese 2016-03-15 13:59:13 +01:00 committed by Marek Vasut
parent f7f601002d
commit 2ef117fe4f
1 changed files with 0 additions and 3 deletions
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3
common/usb_hub.c
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@ -275,7 +275,6 @@ int usb_hub_port_connect_change(struct usb_device *dev, int port)
if (!(portstatus & USB_PORT_STAT_CONNECTION)) if (!(portstatus & USB_PORT_STAT_CONNECTION))
return -ENOTCONN; return -ENOTCONN;
} }
mdelay(200);
/* Reset the port */ /* Reset the port */
ret = legacy_hub_port_reset(dev, port, &portstatus); ret = legacy_hub_port_reset(dev, port, &portstatus);
@ -285,8 +284,6 @@ int usb_hub_port_connect_change(struct usb_device *dev, int port)
return ret; return ret;
} }
mdelay(200);
switch (portstatus & USB_PORT_STAT_SPEED_MASK) { switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
case USB_PORT_STAT_SUPER_SPEED: case USB_PORT_STAT_SUPER_SPEED:
speed = USB_SPEED_SUPER; speed = USB_SPEED_SUPER;