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author | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
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committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
commit | 15dfd0df63ce6847081d09b2bbd567cc0cc4eae1 (patch) | |
tree | 3b73f24fcef970bfcace3cbb297cfa57f3994682 /Documentation/fb/udlfb.txt | |
parent | 328aa7a45af61bc0060c80847daa67fef7b9c0d0 (diff) | |
parent | 0149138c4142da287d23f9d5c6038f7fb5e30ac2 (diff) | |
download | kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.zip kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.gz kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.bz2 |
initial merge with 3.2.72
Diffstat (limited to 'Documentation/fb/udlfb.txt')
-rw-r--r-- | Documentation/fb/udlfb.txt | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/Documentation/fb/udlfb.txt b/Documentation/fb/udlfb.txt index 7fdde2a..57d2f29 100644 --- a/Documentation/fb/udlfb.txt +++ b/Documentation/fb/udlfb.txt @@ -87,23 +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 ================ |