Wine project: Support third party LDDM graphic drivers

[Claude Mench]

hello all,

don't bother on this message if you feel it has nothing to be here.

But I rencently read a whole lot of MSDN documentation about the LDDM
infrastructure. The new Windows graphics vista driver model.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/Display_d/h...

And what made me think we could have support for it in linux.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/Display_d/h...

It seem to me that having the most important parts of the driver
being in user mode would really help to use it on other systems.
> From what I read, the user mode driver would create the command

buffer that would need to be uploaded to the GPU and a kernel
module would need to schedule GPU access handle memory of the
GPU and send the command buffer to it.

This would need the Wine Expertise of DirectX reimplementation as
well as some good kernel hacker, but in the end maybe the struggle
to have linux specific support from Graphics adapter vendors could
be one for all removed if we had LDDM driver support and then and
X build on top of it (same philosofy as Xgl).

it could also benefit to the wine project itself as we would have
really windows driver being used, it should help to increase
compatibility.

sorry if it sound crazy...

[Stefan Dösinger]

Hello,
> This would need the Wine Expertise of DirectX reimplementation as
> well as some good kernel hacker, but in the end maybe the struggle
> to have linux specific support from Graphics adapter vendors could
> be one for all removed if we had LDDM driver support and then and
> X build on top of it (same philosofy as Xgl).

I haven't looked at the tecnical side of this, but while support for LDDM 
drivers might bring the advantages above, it also has drawbacks:

* It might be a part of Wine functionality that is limited to Linux.
* It will always be limited to X86 and X86_64 architectures only.

The Linux graphics driver situation is not bad, in my opinion. The nvidia 
driver is good, some say it's better than the windows driver. The ati fglrx 
driver's quality isn't that shiny, and I have a lot of problems with it, but 
it's getting better and better. The intel graphics chips have Open Source 
drivers, as do the ATI radeon chips, and the nvidia chips(2D only).

The bigest problems are Linux specific graphic functionalities, like Xinerma, 
and Windows drivers will never ever help with this - Look at the ndiswrapper 
project, it will never be able to provide a master mode, because ndis doesn't 
support it.
One thing that could improve is the 3D acceleration speed, but I doubt it will 
be much better. Take the ATI cards: The Linux driver is slow compared to the 
Windows driver. But when I played some games in Windows on my notebook(Radeon 
9000 Mobility) the last time(1 Year ago, approximately), this was true for 
DirectX games only. A friend of mine, who has the same hardware, still has 
problems with OpenGL games like Half-Life 1 and Jedi Academy in WinXP, games 
that perform really fine with fglrx in Wine.

Implementing a wrapper for windows graphics drivers is surely technically 
interesting, it's an unnecessary effort, which is better invested 
elsewhere(For example in making the native Linux drivers better). And it is 
definitly a thing that ReactOS should have.

Stefan

[Krzysztof Foltman]

Stefan Dösinger wrote:
> Implementing a wrapper for windows graphics drivers is surely technically 
> interesting, it's an unnecessary effort, which is better invested 
> elsewhere(For example in making the native Linux drivers better).

Haven't I heard something analogical before?

That'd be... let's see... Wine myth.. #2?

There will always be some obscure cards whose manufacturers just don't 
care about Linux.

(-: Are you going to betray everyone that doesn't buy from Nvidia and 
ATI? :-)

Krzysztof

[Stefan Dösinger]

> Haven't I heard something analogical before?
> That'd be... let's see... Wine myth.. #2?

I know of this, and I agree that Wine is a good thing(Otherwise I wouldn't 
read this list and do any development)

But in my opinion, there's a difference in that matter between Applications 
and Drivers. An application is just something, that sits on top of my Linux 
installation, while a driver is part of really low-level things.
> There will always be some obscure cards whose manufacturers just don't
> care about Linux.

That is true, I cannot deny it. But how many Windows only applications are 
there, and how much Windows-only hardware is out there?

I have started a discussion like this on ndiswrapper-devel some time ago, it 
was about writing a general windows device driver wrapper. No one had a 
answer wheter such a thing was bad for Linux[1], but the suggestion was 
dropped because it was too much work for relatively few devices.

(The situation why ndiswrapper came into existance was that there was a really 
high percentatge of unsupported wlan cards, perhaps due to FCC regulations. 
The FCC states that those cards may only use a certain frequency with a 
limited power level. Many cards have this control implemented in the driver, 
so the manufacturers where not allowed to publish an open source driver or 
the cards specs. And writing a binary only Linux device driver is not 
comparable to writing a closed-source Linux app.
For example, the madwifi driver is basically open source, but it contains a 
binary only HAL module. The author of the driver wrote this module, but he 
was told that he wasn't allowed to release the source.)

It is different on the application side: Publishing a binary-only app is not 
magic, you don't need some open-source glue around the binary module and 
partially recombile the driver against 1001 different kernel versions - So 
companies to not have the pressure to release their sources(which many do not 
like). And it's much more likely that you need one specific application, than 
to need one specific device. It's easier to change an unsupported graphics 
card than to find a 100% compatible program to Microsoft Access. Windows 
users often go to the shop and by a replacement device, if the one they have 
doesn't work out of the box, although they could just download a driver, 
which is faster and cheaper.

Furthermore there's a dependency problem: If I run a Windows application in 
Linux, there's no problem to terminate that application, the rest of the 
system will still run. If I have a device driver, I won't be able to use my 
Linux system without that piece of Win32 code. In such a situation Microsoft 
might argue that we aren't even able to boot our OS without their code.
> (-: Are you going to betray everyone that doesn't buy from Nvidia and
> ATI? :-)

Just out of curiosity: Can you name any graphics card which doesn't have a 
Linux driver? I haven't seen such a device yet.

Relying on Windows drivers would, on the oder hand, betray anyone who is not 
using x86 hardware.

Stefan

[1]: It turned out that there are some Wlan device manufacturers which deny to 
write Linux drivers and tell Linux users to use the Win32 driver and 
Ndiswrapper. It was said that there was even one company which stopped their 
Linux driver development due to ndiswrapper. On the other hand, the Linux 
wlan driver situation is not as bad as it was 2 years ago: Drivers were 
released for the Intel pro/wireless cards(Centrino!), the realtek wlan chip 
and others. The only chip that needs ndiswrapper that I know is the broadcom 
chip, and there's a reverse engineering in progress.
One curiosity about the broadcom chip: There is a Linux driver, it's used in a 
wireless lan access point which uses Linux. I don't know why Broadcom didn't 
release their driver.

[Claude Mench]

----- Original Message ----- 
From: "Stefan Dösinger" 
To: "Claude Mench" 
Cc: 
Sent: Saturday, 2005 October 22 19:47
Subject: Re: Wine project: Support third party LDDM graphic drivers
> The Linux graphics driver situation is not bad, in my opinion. The nvidia
> driver is good, some say it's better than the windows driver. The ati

fglrx
> driver's quality isn't that shiny, and I have a lot of problems with it,

but
> it's getting better and better. The intel graphics chips have Open Source
> drivers, as do the ATI radeon chips, and the nvidia chips(2D only).

You are certainly right in the current situation, but like Microsoft points
it
out in their technical documentation, have you seen how well multiple 3d
apps
coexist ? launched several glxgears ? the LDDM adresses problem that would
need to be adressed also under linux when the GPU will be used to render the
desktop and support multiple direct rendering applications. So right now all
this could seem overkill. But trying to bring the LDDM support
infrastructure
under Linux would help adress several real technical issues like memory
management and multiple GPU support.

So beside having drivers support from all manufacturers it would give
enhancement
of the possibilities of full gpu utilisation.