i bought a usb wireless card TP-Link WN821Nv4 with idVendor=0bda and idProduct=8178, which shows it's a realtek 8192cu card. although i'm using linux kernel 3.2.6, which includes a module called rtl8192cu, from the source i could see there's no support for the specific idVendor and idProduct. i downloaded the driver source from the official realtek website, which does support the idVendor and idProduct, and compiled the driver successfully, i could see wlan1 using ip link show, and there is an entry called wlan1 under /sys/class/net. however, neither iw nor wpa_supplicant would work, they all complain that there is no such device, it seems that the corresponding /sys/class/ieee80211/wlan1 entry is missing. another usb wireless card wlan0 is working normally on the system, and i compared /sys/class/net/wlan0 and /sys/class/net/wlan1, the only one missing is a symbolic link called phy80211 pointing to /sys/class/ieee80211... any idea why this is happening? iw dev wlan1 info command failed: No such device (-19) wpa_supplicant -c someconf -i wlan1 -d wpa_supplicant v1.0 random: Trying to read entropy from /dev/random Initializing interface 'wlan1' conf 'someconf' driver 'default' ctrl_interface 'N/A' bridge 'N/A' Configuration file 'someconf' -> 'someconf' Reading configuration file 'someconf' Priority group 0 id=0 ssid='somessid' Could not open file /sys/class/net/wlan1/phy80211/name: No such file or directory rfkill: initial event: idx=0 type=1 op=0 soft=0 hard=0 nl80211: Set mode ifindex 6 iftype 2 (STATION) nl80211: Failed to set interface 6 to mode 2: -19 (No such device) nl80211: Try mode change after setting interface down nl80211: Set mode ifindex 6 iftype 2 (STATION) nl80211: Failed to set interface 6 to mode 2: -19 (No such device) nl80211: Interface mode change to 2 from 0 failed nl80211: Could not configure driver to use managed mode netlink: Operstate: linkmode=0, operstate=6 nl80211: Set mode ifindex 6 iftype 2 (STATION) nl80211: Failed to set interface 6 to mode 2: -19 (No such device) nl80211: Try mode change after setting interface down nl80211: Set mode ifindex 6 iftype 2 (STATION) nl80211: Failed to set interface 6 to mode 2: -19 (No such device) nl80211: Interface mode change to 2 from 0 failed wlan1: Failed to initialize driver interface Failed to add interface wlan1 wlan1: Cancelling scan request wlan1: Cancelling authentication timeout dmesg from the wlan1 driver: [ 2537.374661] rtw driver version=v3.4.3_4369.20120622 [ 2537.380171] Build at: Sep 1 2012 13:52:58 [ 2537.385927] register rtw_netdev_ops to netdev_ops [ 2537.391583] CHIP TYPE: RTL8188C_8192C [ 2537.397244] [ 2537.397246] usb_endpoint_descriptor(0): [ 2537.408120] bLength=7 [ 2537.413582] bDescriptorType=5 [ 2537.419078] bEndpointAddress=81 [ 2537.424544] wMaxPacketSize=200 [ 2537.429913] bInterval=0 [ 2537.435244] RT_usb_endpoint_is_bulk_in = 1 [ 2537.440624] [ 2537.440626] usb_endpoint_descriptor(1): [ 2537.450986] bLength=7 [ 2537.456117] bDescriptorType=5 [ 2537.461147] bEndpointAddress=2 [ 2537.466243] wMaxPacketSize=200 [ 2537.471125] bInterval=0 [ 2537.475760] RT_usb_endpoint_is_bulk_out = 2 [ 2537.480458] [ 2537.480460] usb_endpoint_descriptor(2): [ 2537.489402] bLength=7 [ 2537.493733] bDescriptorType=5 [ 2537.497926] bEndpointAddress=3 [ 2537.502099] wMaxPacketSize=200 [ 2537.506073] bInterval=0 [ 2537.509887] RT_usb_endpoint_is_bulk_out = 3 [ 2537.513856] [ 2537.513858] usb_endpoint_descriptor(3): [ 2537.521544] bLength=7 [ 2537.525452] bDescriptorType=5 [ 2537.529399] bEndpointAddress=84 [ 2537.533343] wMaxPacketSize=40 [ 2537.537275] bInterval=1 [ 2537.541104] RT_usb_endpoint_is_int_in = 4, Interval = 1 [ 2537.545186] nr_endpoint=4, in_num=2, out_num=2 [ 2537.545189] [ 2537.553163] USB_SPEED_HIGH [ 2537.557627] Chip Version ID: VERSION_NORMAL_TSMC_CHIP_92C. [ 2537.562081] RF_Type is 2!! [ 2537.566879] EEPROM type is E-FUSE [ 2537.571336] ====> ReadAdapterInfo8192C [ 2537.576120] Boot from EFUSE, Autoload OK ! [ 2537.723758] EEPROMVID = 0x0bda [ 2537.728133] EEPROMPID = 0x8178 [ 2537.566879] EEPROM type is E-FUSE [ 2537.571336] ====> ReadAdapterInfo8192C [ 2537.576120] Boot from EFUSE, Autoload OK ! [ 2537.723758] EEPROMVID = 0x0bda [ 2537.728133] EEPROMPID = 0x8178 [ 2537.732330] EEPROMCustomerID : 0x00 [ 2537.736555] EEPROMSubCustomerID: 0x00 [ 2537.740796] RT_CustomerID: 0x00 [ 2537.745040] _ReadMACAddress MAC Address from EFUSE = 6c:e8:73:bf:97:30 [ 2537.749722] EEPROMRegulatory = 0x0 [ 2537.754358] _ReadBoardType(0) [ 2537.758898] BT Coexistance = disable [ 2537.763473] RT_ChannelPlan: 0x02 [ 2537.767994] _ReadPSSetting...bHWPwrPindetect(0)-bHWPowerdown(0) ,bSupportRemoteWakeup(0) [ 2537.778058] ### PS params=> power_mgnt(1),usbss_enable(0) ### [ 2537.783578] ### AntDivCfg(0) [ 2537.789119] readAdapterInfo_8192CU(): REPLACEMENT = 1 [ 2537.794760] <==== ReadAdapterInfo8192C in 223 ms [ 2537.801159] rtw_macaddr_cfg MAC Address = 6c:e8:73:bf:97:30 [ 2537.806968] MAC Address from pnetdev->dev_addr= 6c:e8:73:bf:97:30 [ 2537.816145] bDriverStopped:1, bSurpriseRemoved:0, bup:0, hw_init_completed:0 [ 2537.823404] usbcore: registered new interface driver rtl8192cu [ 2823.516027] +871x_drv - drv_open, bup=0 [ 2823.526453] ===> FirmwareDownload91C() fw:Rtl819XFwImageArray_TSMC [ 2823.526459] FirmwareDownload92C accquire FW from embedded image [ 2823.526465] fw_ver=v80, fw_subver=0, sig=0x88c0 [ 2823.554564] fw download ok! [ 2823.554569] Set RF Chip ID to RF_6052 and RF type to 2. [ 2823.961311] IQK:Start!!! [ 2823.981186] Path A IQK Success!! [ 2823.993686] Path B IQK Success!! [ 2824.009685] Path A IQK Success!! [ 2824.021561] Path B IQK Success!! [ 2824.032937] IQK: final_candidate is 0 [ 2824.039247] IQK: RegE94=100 RegE9C=5 RegEA4=f8 RegEAC=3fe RegEB4=101 RegEBC=c RegEC4=f7 RegECC=2 [ 2824.039252] Path A IQ Calibration Success ! [ 2824.060810] Path B IQ Calibration Success ! [ 2824.176811] pdmpriv->TxPowerTrackControl = 1 [ 2824.188067] MAC Address from REG_MACID = 6c:e8:73:bf:97:30 [ 2824.194419] rtl8192cu_hal_init in 678ms [ 2824.200589] MAC Address = 6c:e8:73:bf:97:30 [ 2824.212229] -871x_drv - drv_open, bup=1 [ 2824.218500] ADDRCONF(NETDEV_UP): wlan1: link is not ready [ 2824.224905] (2)871x_drv - drv_close, bup=1, hw_init_completed=1 [ 2824.212229] -871x_drv - drv_open, bup=1 [ 2824.218500] ADDRCONF(NETDEV_UP): wlan1: link is not ready [ 2824.224905] (2)871x_drv - drv_close, bup=1, hw_init_completed=1 [ 2824.232313] rtl8192c_set_FwJoinBssReport_cmd mstatus(0) [ 2824.232806] -871x_drv - drv_close, bup=1 [ 2824.234001] +871x_drv - drv_open, bup=1 [ 2824.234022] -871x_drv - drv_open, bup=1 [ 2824.234485] ADDRCONF(NETDEV_UP): wlan1: link is not ready [ 2826.240096] ==>pwr_state_check_handler .fw_state(0) [ 2826.247193] ==> rtw_ps_cmd , enqueue CMD [ 2826.257815] ==>rtw_ps_processor .fw_state(0) [ 2826.265242] ==>ips_enter cnts:1 [ 2826.272692] ==>power_saving_ctrl_wk_hdl change rf to OFF...LED(0x00028208).... [ 2826.272696] [ 2826.294579] ===> rtw_ips_pwr_down................... [ 2826.302083] ====> rtw_ips_dev_unload... [ 2826.332815] usb_read_port_cancel [ 2826.339932] usb_write_port_cancel [ 2826.346315] ==> rtl8192cu_hal_deinit [ 2826.352436] bkeepfwalive(0) [ 2826.358298] card disble without HWSM........... [ 2826.369067] <=== rtw_ips_pwr_down..................... in 75ms