libs/sys: fix luci.sys.wifi.channels()

diff --git a/libs/sys/luasrc/sys.lua b/libs/sys/luasrc/sys.lua
index 817217b900978e8bb4a7de28a6df69b37a0b0cc5..1cf8b9f1865e4f5e2a0575f2f324a9aaeac82f9e 100644 (file)
--- a/libs/sys/luasrc/sys.lua
+++ b/libs/sys/luasrc/sys.lua
@@ -722,10 +722,14 @@ end
 -- @param iface        Wireless interface (optional)
 -- @return             Table of available channels
 function wifi.channels(iface)
-       local t = iwinfo.type(iface or "")
+       local stat, iwinfo = pcall(require, "iwinfo")
        local cns
-       if iface and t and iwinfo[t] then
-               cns = iwinfo[t].freqlist(iface)
+
+       if stat then
+               local t = iwinfo.type(iface or "")
+               if iface and t and iwinfo[t] then
+                       cns = iwinfo[t].freqlist(iface)
+               end
        end
 
        if not cns or #cns == 0 then