Arch Linux

cppking

Member

Registered: 2012-09-16

Posts: 11

how to enable "fast scrolling" of intel video card?

I fall in love with fbterm,but i don't know how to enable "fast scrolling" in my video card

laptop:ThinkPad x200
video card:
VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
OS:Archlinux

#fbterm -v

[screen] driver:inteldrmfb,mode:1280x800--32bpp,scrolling:redraw
[font].................
[term].............

so anyone can help me ?

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: how to enable "fast scrolling" of intel video card?

I don't know what you mean by fast scrolling... can you explain a bit more what it is you are trying to achieve?  Also what other information have you already found relating to this issue?

Oh and a bit OT, but what is it you like so much about fbterm?  It makes the text super small and funky on my machine.

cppking

Member

Registered: 2012-09-16

Posts: 11

Re: how to enable "fast scrolling" of intel video card?

#man fbterm

PERFORMANCE
       According  test  result,  FbTerm  spends more than 95% time on painting
       screen. Speedup painting will significantly increase performance.  Here
       are some suggestions for frame buffer device:

         *  Enable  fast  scrolling on frame buffer device. The visible screen
       will be just a window of the video memory, when scrolling, FbTerm  only
       change the start of window, no need to repaint the whole screen.

         *  On  Intel  P6  family  processors  the Memory Type Range Registers
       (MTRRs) may be used to control processor access to  memory  ranges.  If
       you  have  video  card  on  a  PCI or AGP bus, enabling write-combining
       allows bus write transfers to be combined into a larger transfer before
       bursting  over  the  PCI/AGP  bus.  This  can  increase  performance of
       FbTerm's paint operations.

       Maybe you need to enable them manually for your video card.  For  exam‐
       ple,  by default fast scrolling and write-combining are all disabled on
       general VESA frame buffer device, GRUB/LILO configure  file  should  be
       modified to enable them.  A GRUB example is showed below:

       title Ubuntu
           root (hd0,0)
           kernel   /boot/vmlinuz   ro   root=LABEL=UBUNTU   splash  vga=0x317
       video=vesafb:ywrap,mtrr:3
           initrd /boot/initrd.img

       You may check fast scrolling status with "fbterm -v",  a  message  with
       "scrolling:   redraw"  means  fast  scrolling  is  disabled,  otherwise
       enabled.

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: how to enable "fast scrolling" of intel video card?

He means the scrolling:redraw thing. With (u)vesafb, redrawing mode is slow as molasses, so you activate ywrap for faster scrolling. I wasn't aware KMS drivers have this stuff too. Though it's possible they actually don't, and fbterm is giving bogus data. I'm going to bed now (it's 5am in the morning here!), but tomorrow I'll check KMS documentation.

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: how to enable "fast scrolling" of intel video card?

I think that this does not apply to you because you are using KMS (or should be at least).  You are using a kind of framebuffer device, but it is not vesa.