Go with these step with Updated Firmware :
Visit
http://192.168.1.1 and login to your router.
Go to Setup > Basic Setup
WAN Connection > disable the connection type,for STP -> Disable
Set the Local IP address to 192.168.x.2 depends on the of the wireless router.
Gateway to 192.168.x.1 and Local DNS to 192.168.x.1
WAN Port : checked the Assign WANT Port to Switch (optional)
After that Go to Wireless > Basic Settings and the following settings
Wireless Mode : Repeater Bridge
Wireless Network Mode : Mixed
Wireless Network Name (SSID)
Wireless Channel : Auto
Channel Width : 20MHz
Wireless SSID Broadcast : Enable
Network Configuration : Bridge
SAVE and APPLY SETTINGS