Messages in this thread | | | Date | Fri, 8 May 2009 11:35:27 +0200 | From | Joerg Roedel <> | Subject | Re: IOMMU and graphics cards |
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On Thu, May 07, 2009 at 11:36:32AM -0700, David Miller wrote: > From: David Woodhouse <dwmw2@infradead.org> > Date: Thu, 07 May 2009 11:22:01 +0100 > > > On Thu, 2009-05-07 at 12:01 +0200, Joerg Roedel wrote: > >> > Looks like the DRM code uses the DMA API. > >> > >> The proprietary drivers make problems so far. For the ATI one I am in > >> contact with the developers to try to fix it. But I can't do anything > >> about the other proprietary driver I am aware of :-( > > > > I see no harm in "breaking" code which was already broken. If that's the > > only reason we're enabling the graphics workaround, let's turn it off. > > Seriously, this is an enormous price to pay just for one bad apple > proprietary driver. > > I can't believe the level of concessions some people are suggesting.
This concession is already in the VT-d code. And this concession is _enabled_ in enterprise distribtions supporting VT-d. I don't like the way it is implemented there and I definitly will not implement a similar way for the AMD IOMMU. What I try to achieve is a consistent solution for both IOMMUs. Having the broken drivers work on VT-d but not on AMD IOMMU is clearly a bad solution.
The other way to achieve consistency is to remove the workaround from VT-d code which significantly increases the chance to get the broken stuff fixed. David?
> Let's not make IOMMU's basically useless by working around one broken > driver.
Agreed.
> Proper interfaces for what this driver is trying to do have existed in > the kernel for 10+ years. There are no excuses, and it's time for > Nvidia to get with the game plan.
Agreed.
Joerg
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