Raspberry Pi Forums

I notice in the kernel source I got from github.com/raspberrypi (Linux 3.18.3) that in drivers/net/wireless/Kconfig, the line that would source the Kconfig of the rtlwifi directory (which is immediately below us) is commented out. It is not commented out in any sources I've downloaded from kernel.org. Why is this? It's of especial concern to me because (1) the popular Edimax EW-7811Un Wifi dongle is an rtl8188 device, and the rti8188 device driver is in that rtlwifi directory which the RPi kernel source has been made to skip.

strnbrg59 wrote:I notice in the kernel source I got from github.com/raspberrypi (Linux 3.18.3) that in drivers/net/wireless/Kconfig, the line that would source the Kconfig of the rtlwifi directory (which is immediately below us) is commented out. It is not commented out in any sources I've downloaded from kernel.org. Why is this? It's of especial concern to me because (1) the popular Edimax EW-7811Un Wifi dongle is an rtl8188 device, and the rti8188 device driver is in that rtlwifi directory which the RPi kernel source has been made to skip.

That driver was replaced at least 2 years ago, because of problems with it and the Pi, by the driver in this directory drivers/net/wireless/rtl8192cu, the official Realtek 8188CUS driver, which works well with the EW-7811Un.


MrEngman

MrEngman wrote: drivers/net/wireless/rtl8192cu, the official Realtek 8188CUS driver, which works well with the EW-7811Un.
MrEngman

Thanks. I notice that on my Linux laptop, when rtl8192cu gets inserted, it pulls in three more modules -- rtl_usb, rtlwifi and rtl8192c_common. None of those exist on my Pi, but neither do they appear to be needed, and indeed nm shows very different results for the two rtl8192cu's -- the laptop one and the Pi one.

So, per DougieLawson at viewtopic.php?p=759957#p759957, are you also inclined to suggest my problem is that my Pi A+ isn't supplying enough power to the Edimax?

strnbrg59 wrote:

MrEngman wrote: drivers/net/wireless/rtl8192cu, the official Realtek 8188CUS driver, which works well with the EW-7811Un.
MrEngman

Thanks. I notice that on my Linux laptop, when rtl8192cu gets inserted, it pulls in three more modules -- rtl_usb, rtlwifi and rtl8192c_common. None of those exist on my Pi, but neither do they appear to be needed, and indeed nm shows very different results for the two rtl8192cu's -- the laptop one and the Pi one.

So, per DougieLawson at viewtopic.php?p=759957#p759957, are you also inclined to suggest my problem is that my Pi A+ isn't supplying enough power to the Edimax?

What DougieLawson was suggesting was the power supply you are using to power your Pi A+ may not be sufficient, not the Pi A+ could not supply enough power to the wifi dongle. It's a fairly common problem. Depends on you power supply spec.

Regarding the wifi's LED. I have several different wifi modules that use different drivers that refuse to flash the LED sometimes.


MrEngman

MrEngman wrote: What DougieLawson was suggesting was the power supply you are using to power your Pi A+ may not be sufficient, not the Pi A+ could not supply enough power to the wifi dongle.

I'm powering my Pi from the USB cable+adapter that came with my Android phone, plugged into my house's 120V AC. The adapter claims to be good for 1 Amp at 5 V.

The Edimax is simply not recognized; it doesn't show up if I type "lsusb". (The kernel detects *something* but doesn't get very far, as I've detailed in that exchange with Dougie).

I just checked the voltage drop across the Pi's VCC and GND pins. Without the Edimax, it's 4.93V. With the Edimax it's still 4.93V.

Problem solved by adding "dwc_otg.speed=1" to my /boot/cmdline.txt. That limits me to USB 1.1, which at 12 Mbps is still far more than what my Wifi access point can ever supply.