[Intel-gfx] i915-related and general system freezes with specific kernel config // IOMMU

[Daniel Vetter]

On Sun, Jan 20, 2013 at 10:52 PM, Mihai Moldovan <ionic at ionic.de> wrote:
> the patch does work, i.e., it turns off DMAR for the graphics card and
> alleviates the freezes when loading i915/kms.
>
> However, still seeing random machine freezes with it (being consistent with the
> behavior I've experienced with intel_iommu=igfx_off).

Thanks for testing, I've just submitted the patch for review. It
should included in a -fixes tree soon and the get backported to stable
kernels.

> The patch + forcing RWBF is working, too. Interestingly, this version didn't
> randomly freeze yet, after more than 5 hours of uptime! I'll leave the box
> running until tomorrow to make sure I did stick around long enough.
>
> All those tested kernels were able to handle USB and PCI(e) devices.
>
> I still have to test turning off IOMMU in general and Intel IOMMU specifically.
> Will probably do this tomorrow.

Please let me know when this works solidly for you, so that I can put
it into a real patch and also submit it for inclusion.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch