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Re: Free Linux Driver Development!

From:  "Dave Airlie" <airlied-AT-gmail.com>
To:  "Roland Dreier" <rdreier-AT-cisco.com>
Subject:  Re: Free Linux Driver Development!
Date:  Wed, 31 Jan 2007 09:14:44 +1100
Cc:  "Greg KH" <greg-AT-kroah.com>, "Jeff Garzik" <jeff-AT-garzik.org>, linux-kernel-AT-vger.kernel.org
Archive-link:  Article, Thread

>  > There was a wireless-mini-summit a week or so ago, so those developers
>  > all know what is going on in that space right now.  They are facing a
>  > number of different regulatory issues, combined with lack of
>  > specifications from some vendors.  I don't think that the developers who
>  > actually have specs are complaining about anything right now.
>
> OK, one last reply before I give up on this thread...
>
> Sure, Ralink drivers will get upstream eventually.  But by the time
> the drivers get merged, Ralink will have stopped making the chips that
> it supports (or so I read, http://www.linuxemporium.co.uk/products/wireless/)!
> I don't think that taking a year or two to merge a driver is going to
> impress a vendor, especially since the reverse-engineered Broadcom
> wireless driver is probably going to go upstream at just about the
> same time.
>
> An uncharitable vendor might decide it's not worth publishing specs,
> since the Linux guys can reverse engineer the Windows driver just as
> fast anyway.

I'm sort of with Roland on this, the timelines aren't usually worth it
for a company to bother especially with complicated hardware, the time
taken to do a community graphics driver for any GPU where specs have
been available approaches infinity, unless the vendor actually does
the driver or pays someone to do the driver the hope of a community
supported driver reaching maturity while the product is still
available is slim.... for anyone desparate to start writing device
drivers, XGI have recently dropped a load of specs for their cards,
I'm not seeing anyone other than the usual GPU ppl step up an do
anything and as I said the time it takes a single volunteer to write a
GPU driver is a lot longer than the card...

Dave.


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Re: Free Linux Driver Development!

Posted Feb 1, 2007 8:02 UTC (Thu) by kune (guest, #172) [Link]

Dumping specs into the open helps, but might also rather frustrating. There are other things the vendor should do:

1) Have a contact person, who has enough time and the know-how to answer technical questions, because documentation will be buggy and incomplete
2) Provide also a channel to handle firmware bugs.
3) Provide new hardware to the developers
4) Convince the marketing people, that reasonable specs on the package is good for revenue. This helps customers to find out, that the device is actually supported by Linux.
5) If deadlines are important, spend money for developer resources.

Re: Free Linux Driver Development!

Posted Feb 1, 2007 10:20 UTC (Thu) by ortalo (subscriber, #4654) [Link]

This is true only for a whole new driver. Most GPU are an evolution of the previous version and drivers usually adress a whole family of GPUs. So even if rewriting a full new driver from scratch could take one year, adapting it afterwards for the n+2 generation of GPU that got out in the meantime would probably take only 1 week...

Re: Free Linux Driver Development!

Posted Feb 2, 2007 4:11 UTC (Fri) by airlied (subscriber, #9104) [Link]

This is fine until the GPU takes a big step forward, like say the radeon r500 series, or the ATI IGP chipsets, or the nvidia G80, or when shaders arrived on most cards etc..

the new i965 is a lot lot different in terms of 3D engine than the previous generation...

Re: Free Linux Driver Development!

Posted Feb 1, 2007 13:29 UTC (Thu) by gouyou (subscriber, #30290) [Link]

Also happens that the specs are released at the same times as the hardware, and currently you see a new line of GPUs released every 6 months. So ...

Re: Free Linux Driver Development!

Posted Feb 1, 2007 23:52 UTC (Thu) by hazelsct (guest, #3659) [Link]

Hmm. It's tempting to say, "If free software driver authors got specs when Windows driver authors got them, we'd be all set."

However, Windows driver authors are generally in-house, and developing the driver in tandem with the hardware. So the only solution is to grow the desktop Linux market to the point where hardware makers who support it -- with *free* drivers -- see a monetarily significant advantage relative to those who don't. And that takes time!

Re: Free Linux Driver Development!

Posted Feb 1, 2007 20:10 UTC (Thu) by etrusco (guest, #4227) [Link]

I'd like to mod him "-1: Flamebait" :-P

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