Merge branch 'next/timer' of git://git.linaro.org/people/arnd/arm-soc

[pandora-kernel.git] / Documentation / fb / udlfb.txt

diff --git a/Documentation/fb/udlfb.txt b/Documentation/fb/udlfb.txt
index 473ceed..57d2f29 100644 (file)
--- a/Documentation/fb/udlfb.txt
+++ b/Documentation/fb/udlfb.txt
@@ -87,28 +87,38 @@ Special configuration for udlfb is usually unnecessary. There are a few
 options, however.
 
 From the command line, pass options to modprobe
-modprobe udlfb defio=1 console=1
+modprobe udlfb fb_defio=0 console=1 shadow=1
 
-Or for permanent option, create file like /etc/modprobe.d/options with text
-options udlfb defio=1 console=1
+Or modify options on the fly at /sys/module/udlfb/parameters directory via
+sudo nano fb_defio
+change the parameter in place, and save the file.
 
-Accepted options:
+Unplug/replug USB device to apply with new settings
+
+Or for permanent option, create file like /etc/modprobe.d/udlfb.conf with text
+options udlfb fb_defio=0 console=1 shadow=1
+
+Accepted boolean options:
 
 fb_defio       Make use of the fb_defio (CONFIG_FB_DEFERRED_IO) kernel
                module to track changed areas of the framebuffer by page faults.
-               Standard fbdev applications that use mmap but that do not
-               report damage, may be able to work with this enabled.
-               Disabled by default because of overhead and other issues.
-
-console                Allow fbcon to attach to udlfb provided framebuffers. This
-               is disabled by default because fbcon will aggressively consume
-               the first framebuffer it finds, which isn't usually what the
-               user wants in the case of USB displays.
+               Standard fbdev applications that use mmap but that do not
+               report damage, should be able to work with this enabled.
+               Disable when running with X server that supports reporting
+               changed regions via ioctl, as this method is simpler,
+               more stable, and higher performance.
+               default: fb_defio=1
+
+console        Allow fbcon to attach to udlfb provided framebuffers.
+               Can be disabled if fbcon and other clients
+               (e.g. X with --shared-vt) are in conflict.
+               default: console=1
 
 shadow         Allocate a 2nd framebuffer to shadow what's currently across
                the USB bus in device memory. If any pixels are unchanged,
                do not transmit. Spends host memory to save USB transfers.
                Enabled by default. Only disable on very low memory systems.
+               default: shadow=1
 
 Sysfs Attributes
 ================