Comment 2 for bug 436702

Finally I've solved my problem, now I'll explain briefly steps I did.

- First of all I've recompiled a patched kernel 2.6.31, in particular there's a little change to do in the file /usr/src/linux-source-2.6.31/drivers/input/keyboard/atkbd.c, without this step pressing the brightness button locks the keyboard,
you have to add your model after others Samsung, I've added these lines:

 {
  .ident = "Samsung R519/R719",
  .matches = {
   DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
   DMI_MATCH(DMI_PRODUCT_NAME, "R519/R719"),
  },
  .callback = atkbd_setup_forced_release,
  .driver_data = atkbd_samsung_forced_release_keys,
 },

- Second step, I've added info about my pc on /usr/share/hal/fdi/information/10freedesktop/30-keymap-misc.fdi
Just a little change, string

      <match key="/org/freedesktop/Hal/devices/computer:system.hardware.vendor" prefix_ncase="samsung">
 <match key="/org/freedesktop/Hal/devices/computer:system.hardware.product" contains_outof="NC10;SP55S;SQ45S70S;SX60P;SX30S;R59P/R60P/R61P;Q210;Q310;X05">

becomes

      <match key="/org/freedesktop/Hal/devices/computer:system.hardware.vendor" prefix_ncase="samsung">
 <match key="/org/freedesktop/Hal/devices/computer:system.hardware.product" contains_outof="NC10;SP55S;SQ45S70S;SX60P;SX30S;R59P/R60P/R61P;Q210;Q310;X05;R519/R719">

- Last step, I gave the command xrandr --output LVDS --set BACKLIGHT_CONTROL legacy , it's possible to add this command in Sessions.

Now I can control brightness with fn keys and with brightness applet. There's only one little issue, if I set brightness to minimum, screen goes black and it's impossible to revert the situation, I need to switch to the console (Ctrl+Alt+F1) and than come back to X.

It would be great if a patch will be placed in next Karmic, it's not amazing recompiling kernel each time.