Tests:SDIO-with-UHS

This document describes how to test SDIO at UHS speeds using a ZComax AC-180M card.


 * Note: This is a draft! The final version will be updated until 2016-11-15.

Setup
The following items are needed for this test:


 * the client - a Salvator-X board with a H3 SoC and a ZComax AC-180M plugged into CN13
 * the server - a second computer running some Linux distribution with iperf3 installed
 * the network - capable of running 802.11ac

The client will be connected to the network via WIFI (802.11ac). The server is preferably connected to the network via Gigabit-LAN. Although connection with 802.11ac is also possible, the WIFI card of the server is unknown and might affect the measurement. Gigabit-LAN is more reliable in this regard.

The setup used for the below results is:


 * the client - a Salvator-X board with a H3 SoC and a ZComax AC-180M plugged into CN13
 * the server - Fujitsu Lifebook E544 with RTL8111/8168 PCI Express Gigabit Ethernet controller running Debian Stretch
 * the network - a Fritzbox 7560 router with 802.11ac and Gigabit-LAN

Ensure the driver is activated in the kernel config
FIXME

Prepare the root filesystem for your target
The root filesystem should have:


 * busybox with udhcpc (v1.24.2 used here)
 * wireless-tools (v3.0-pre9 used here)
 * wpa-supplicant (v2.5 used here)
 * iperf3 (v3.1.2 used here)

All tools are available via the buildroot buildsystem.

Boot the kernel
You should see this on successful probe: FIXME

Verify SD card speed and bus width
We want a UHS mode:

FIXME: add
 * 1) cat /sys/kernel/debug/mmc0/ios

Now scan for networks
FIXME: add output
 * 1) iwlist wlan0 scan

Create /etc/wpa_supplicant.conf for your network
Here is a template: ctrl_interface=/var/run/wpa_supplicant network={ ssid=" " scan_ssid=1 key_mgmt=WPA-PSK psk=" " }

Start wpa_supplicant to connect to the network
FIXME: Verify command and add log output
 * 1) wpa_supplicant -Dwext -iwlan0 -c /etc/wpa_supplicant.conf &

Start the iperf3 (server mode) on the server
$ iperf3 -s --- Server listening on 5201 ---

Get an address and say hello to the iperf3 server
FIXME: add output ...
 * 1) udhcpc -i wlan0; ping 

Test the connection with iperf3
On the target board, run:

$ iperf3 -c 