diff --git a/Documentation/fb/vesafb.txt b/Documentation/fb/vesafb.txt index 814e2f56a6ad..62db6758d1c1 100644 --- a/Documentation/fb/vesafb.txt +++ b/Documentation/fb/vesafb.txt @@ -144,7 +144,21 @@ vgapal Use the standard vga registers for palette changes. This is the default. pmipal Use the protected mode interface for palette changes. -mtrr setup memory type range registers for the vesafb framebuffer. +mtrr:n setup memory type range registers for the vesafb framebuffer + where n: + 0 - disabled (equivalent to nomtrr) + 1 - uncachable + 2 - write-back + 3 - write-combining (default) + 4 - write-through + + If you see the following in dmesg, choose the type that matches the + old one. In this example, use "mtrr:2". +... +mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining +... + +nomtrr disable mtrr vremap:n remap 'n' MiB of video RAM. If 0 or not specified, remap memory