Problem with Matrox MGA G200eW video driver.

[Marko Vojinovic]

On Thu, 15 Aug 2013 16:36:24 -0700
Ben Greear <greearb at candelatech.com> wrote:

> I have a fancy and quite new E5 processor server system that has a
> Matrox VGA port in it:
> 
> e:04.0 VGA compatible controller: Matrox Electronics Systems Ltd. MGA
> G200eW WPCM450 (rev 0a)
> 
> This appears to use the mgag200 kernel module.
> 
> When this module is loaded, the Xorg log complains saying the module
> must be unloaded and I end up running 'llvmpipe' and performance is
> horrible.
> 
> If I blacklist the module, it still runs in emulation mode and
> performance is horrible.
> 
> Here is what I think is the interesting part for the black-list
> variant:
> 
> [    26.079] (II) Module vgahw: vendor="X.Org Foundation"
> [    26.079]    compiled for 1.14.2, module version = 0.1.0
> [    26.079]    ABI class: X.Org Video Driver, version 14.1
> [    26.079] (--) MGA(0): Chipset: "mgag200 eW Nuvoton"
> [    26.079] (--) MGA(0): Linear framebuffer at 0xF9000000
> [    26.079] (--) MGA(0): MMIO registers at 0xFB800000
> [    26.079] (--) MGA(0): Pseudo-DMA transfer window at 0xFB000000
> [    26.150] (II) MGA(0): Creating default Display subsection in
> Screen section "Default Screen Section" for depth/fbbpp 24/32
> [    26.150] (==) MGA(0): Depth 24, (--) framebuffer bpp 32
> [    26.150] (==) MGA(0): RGB weight 888
> [    26.150] (**) MGA(0): Enabling KVM
> [    26.150] (==) MGA(0): Using HW cursor
> [    26.150] (**) MGA(0): Using "Shadow Framebuffer" - acceleration
> disabled [    26.150] (--) MGA(0): Video BIOS info block at offset
> 0x07D60 [    26.150] (==) MGA(0): VideoRAM: 16320 kByte
> 
> 
> So, first question:  Should I be blacklisting the driver?
> 
> And second, any idea on how to either get the acceleration working,
> or make gnome work OK w/out it?  I don't care at all about 3D affects,
> I just need basic desktop functionality to work w/out too much
> overhead.

While I know basically nothing about Matrox cards, the log line

[    26.150] (**) MGA(0): Using "Shadow Framebuffer" - acceleration disabled

apparently says that acceleration was deliberately disabled in the
config file (i.e. somewhere inside /etc/X11/xorg.conf or inside
xorg.conf.d directory). This is the meaning of the (**).

Also, AFAIK Gnome3 requires accelerated graphics (at least it did last
time I checked). You may be better off trying Mate, XFCE, LXDE, KDE, or
some lightweight window manager without a full DE.

HTH, :-)
Marko