On Wed, Sep 29, 2010 at 4:28 PM, Marathe, Yogesh [off-list ref] wrote:

dsplink and syslink (two drivers who use iommu) should not enable
CONFIG_MPU_BRIDGE_IOMMU as dspbridge and dsplink /syslink
can not co-exist as they are using same resources. Not applying patch
breaks dsplink/sylink any one which is being used. Defining this config
makes them co-exist.

No, for dsp-link you would have:
CONFIG_TIDSPBRIDGE=n
CONFIG_OMAP_IOMMU_IVA2=y

It would be exactly the same as applying your patch.

And tidspbridge is not using iommu right now.

And AFAIK syslink is not for omap3, so omap3_devices is not relevant.

I'm ok with changing name to CONFIG_OMAP_IOMMU_IVA2 but ideally
then that will also break the dspbridge.

No, grep for MPU_BRIDGE_IOMMU on the current tidspbridge in mainline;
it's not defined anywhere, so CONFIG_OMAP_IOMMU_IVA2, or
CONFIG_FOOBAR, it doesn't matter for tidspbridge right now. And
MPU_BRIDGE_IOMMU doesn't depend on tidspbridge on any way.

One more way would be to soure revert the patch and apply on dspbridge branch if it breaks the builds on that branch rather than
breaking others in master.

There is no tidspbrige branch; it's in mainline:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=tree;f=drivers/staging/tidspbridge

But that doesn't matter, even if it was in a branch, iommu should not
break either tidspbridge, or dsp-link, and driver branches should not
modify anything outside their domain (ideally).

All you need to do is 'select OMAP_IOMMU_IVA2', although the attached
patch would be needed.

-- 
Felipe Contreras
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