On 03/10/2016 08:50 AM, Stefan Roese wrote:
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: 24.811 seconds
So ~3.5 seconds of USB scanning time reduction.
These mdelay calls are removed if CONFIG_USB_FAST_SCAN is defined. They
are not removed per default yet. It would be good to test with this
option enabled on many other boards. And once we have a good testing
base we can decide to remove these delays completely, including this
macro.
This patch,
Tested-by: Stephen Warren <swar...@nvidia.com>
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