aboutsummaryrefslogtreecommitdiff
path: root/Documentation/fb/cyblafb/usage
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/fb/cyblafb/usage')
-rw-r--r--Documentation/fb/cyblafb/usage33
1 files changed, 22 insertions, 11 deletions
diff --git a/Documentation/fb/cyblafb/usage b/Documentation/fb/cyblafb/usage
index e627c8f5421..a39bb3d402a 100644
--- a/Documentation/fb/cyblafb/usage
+++ b/Documentation/fb/cyblafb/usage
@@ -40,6 +40,16 @@ Selecting Modes
None of the modes possible to select as startup modes are affected by
the problems described at the end of the next subsection.
+ For all startup modes cyblafb chooses a virtual x resolution of 2048,
+ the only exception is mode 1280x1024 in combination with 32 bpp. This
+ allows ywrap scrolling for all those modes if rotation is 0 or 2, and
+ also fast scrolling if rotation is 1 or 3. The default virtual y reso-
+ lution is 4096 for bpp == 8, 2048 for bpp==16 and 1024 for bpp == 32,
+ again with the only exception of 1280x1024 at 32 bpp.
+
+ Please do set your video memory size to 8 Mb in the Bios setup. Other
+ values will work, but performace is decreased for a lot of modes.
+
Mode changes using fbset
========================
@@ -54,20 +64,26 @@ Selecting Modes
- if a flat panel is found, cyblafb does not allow you
to program a resolution higher than the physical
resolution of the flat panel monitor
- - cyblafb does not allow xres to differ from xres_virtual
- cyblafb does not allow vclk to exceed 230 MHz. As 32 bpp
and (currently) 24 bit modes use a doubled vclk internally,
the dotclock limit as seen by fbset is 115 MHz for those
modes and 230 MHz for 8 and 16 bpp modes.
+ - cyblafb will allow you to select very high resolutions as
+ long as the hardware can be programmed to these modes. The
+ documented limit 1600x1200 is not enforced, but don't expect
+ perfect signal quality.
- Any request that violates the rules given above will be ignored and
- fbset will return an error.
+ Any request that violates the rules given above will be either changed
+ to something the hardware supports or an error value will be returned.
If you program a virtual y resolution higher than the hardware limit,
cyblafb will silently decrease that value to the highest possible
- value.
+ value. The same is true for a virtual x resolution that is not
+ supported by the hardware. Cyblafb tries to adapt vyres first because
+ vxres decides if ywrap scrolling is possible or not.
- Attempts to disable acceleration are ignored.
+ Attempts to disable acceleration are ignored, I believe that this is
+ safe.
Some video modes that should work do not work as expected. If you use
the standard fb.modes, fbset 640x480-60 will program that mode, but
@@ -129,10 +145,6 @@ mode 640x480 or 800x600 or 1024x768 or 1280x1024
verbosity 0 is the default, increase to at least 2 for every
bug report!
-vesafb allows cyblafb to be loaded after vesafb has been
- loaded. See sections "Module unloading ...".
-
-
Development hints
=================
@@ -195,7 +207,7 @@ a graphics mode.
After booting, load cyblafb without any mode and bpp parameter and assign
cyblafb to individual ttys using con2fb, e.g.:
- modprobe cyblafb vesafb=1
+ modprobe cyblafb
con2fb /dev/fb1 /dev/tty1
Unloading cyblafb works without problems after you assign vesafb to all
@@ -203,4 +215,3 @@ ttys again, e.g.:
con2fb /dev/fb0 /dev/tty1
rmmod cyblafb
-