Wednesday, September 09, 2009

Uji Coba Flexinet Di Ubuntu Jaunty

Beberapa hari ini saya mencoba memakai Flexinet untuk menyambung ke Internet. Modem yang dipakai bermerek Skydata model BRG-U100. Dari lsusb, IDnya adalah 2227:3105. Dari lsusb -v akan muncul info lebih lengkap, idVendor 0x2227 = Samwoo Enterprise, sedangkan idProduct 0x3105 = Skydata SKD-U100. Ternyata modem CDMA tersebut tidak selalu langsung dikenal oleh Ubuntu Jaunty, yang akan menampilkan pesan berikut di syslog:

Sep  8 22:07:50 quirk-a kernel: [ 1457.112160] usb 4-2: new full speed USB device using uhci_hcd and address 3
Sep 8 22:07:50 quirk-a kernel: [ 1457.349099] usb 4-2: configuration #1 chosen from 1 choice
Sep 8 22:07:50 quirk-a kernel: [ 1457.352232] cdc_acm 4-2:1.0: ttyACM0: USB ACM device
Sep 8 22:07:57 quirk-a NetworkManager: (ttyACM0): ignoring due to lack of mobile broadband capabilties
Apabila proses deteksi modem lancar, di syslog akan muncul pesan berbeda:
Sep  8 21:48:40 quirk-a kernel: [  307.604159] usb 4-2: new full speed USB device using uhci_hcd and address 2
Sep 8 21:48:41 quirk-a kernel: [ 307.848088] usb 4-2: configuration #1 chosen from 1 choice
Sep 8 21:48:41 quirk-a kernel: [ 307.889370] cdc_acm 4-2:1.0: ttyACM0: USB ACM device
Sep 8 21:48:41 quirk-a kernel: [ 307.966393] usbcore: registered new interface driver cdc_acm
Sep 8 21:48:41 quirk-a kernel: [ 307.966402] cdc_acm: v0.26:USB Abstract Control Model driver for USB modems and ISDN adapters
Sep 8 21:48:47 quirk-a NetworkManager: (ttyACM0): found serial port (udev:CDMA hal:)
Sep 8 21:48:47 quirk-a NetworkManager: (ttyACM0): deferring until all ports found
Sep 8 21:48:51 quirk-a NetworkManager: Re-checking deferred serial ports
Sep 8 21:48:51 quirk-a NetworkManager: (ttyACM0): new Modem device (driver: 'cdc_acm')
Sep 8 21:48:51 quirk-a NetworkManager: (ttyACM0): exported as /org/freedesktop/Hal/devices/usb_device_2227_3105_SKD_U20_000_if0_serial_unknown_0
Analisis sementara, inisialisasi modem ini kadang perlu waktu > 3 detik, padahal program pendeteksi modem di Jaunty diset dengan timeout 3 detik. Solusi sementara adalah cabut-pasang modem sampai Jaunty otomatis mengenali, karena program pendeteksi di /lib/udev/nm-modem-probe memiliki batas timeout 3 detik yang di-hardcode.

Setelah modem terdeteksi, proses setup koneksi via network manager dapat dilakukan seperti biasa. Tidak perlu memakai wizard, karena memang Flexinet belum terdaftar di wizard.

Satu perangkat keras lagi yang tidak perlu driver khusus di Linux! (Walaupun perlu tweaking dan kesabaran untuk dapat memakainya).

Thursday, September 03, 2009

Brain Fuck Scheduler for Linux Kernel (aka Welcome Back Con Kolivas)

Take newest BFS patch from http://ck.kolivas.org/patches/bfs/2.6.30-sched-bfs-203.patch, start from mainline kernel 2.6.30.3, then apply 3 patches:

tar xvfj vanilla/linux-2.6.30.3.tar.bz2 
cd linux-2.6.30.3/
patch -p1 < ../ck/2.6.30-sched-bfs-203.patch
bzip2 -dc ../vanilla/patch-2.6.30.3-4.bz2 | patch -p1
# skip 2 patches to kernel/sched.c and kernel/sched_rt.c above
bzip2 -dc ../vanilla/patch-2.6.30.4-5.bz2 | patch -p1
cd ..
mv linux-2.6.30.3 linux-2.6.30.5-ck
... and now reconfig, compile, reboot, test, loop

ps: don't forget to read BFS FAQ