can't open usb device if connect to pi before raspbian boot

[sxd1140]

i have a usb device connected to pi first

then pi power on

lsusb the usb device not display

usb device plug out and in once

lssub can display this device

how can i fix this

like this viewtopic.php?f=28&t=69505

thanks.

[topguy]

Tell us more about the device.

Look at the output from "dmesg" command in both scenarios and see if there are some errors related to your device.

[peterlite]

There are some USB SATA chips with this problem. Use lsusb. Search for the chip ID you find in lsusb. You will see lines like the following. You want the 0cf3:3005 part.

Code: Select all

Bus 002 Device 005: ID 0cf3:3005 Atheros Communications, Inc. AR3011 Bluetooth

[sxd1140]

at last i let USB device reboot once to solve this issue.

thanks all.