Re: [RFT v2] iommu/amd: use subsys_initcall() on amdv2 iommu

From: Luis R. Rodriguez
Date: Tue Apr 12 2016 - 18:07:27 EST


On Mon, Apr 11, 2016 at 03:52:43PM +0200, Christian König wrote:
> Am 11.04.2016 um 15:39 schrieb Oded Gabbay:
> >On Mon, Apr 11, 2016 at 4:28 PM, Christian König
> ><christian.koenig@xxxxxxx> wrote:
> >>Am 09.04.2016 um 02:25 schrieb Luis R. Rodriguez:
> >>>On Tue, Mar 29, 2016 at 10:41 AM, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote:
> >>>>We need to ensure amd iommu v2 initializes before
> >>>>driver uses such as drivers/gpu/drm/amd/amdkfd/kfd_module.c,
> >>>>to do this make its init routine a subsys_initcall() which
> >>>>ensures its load init is called first than modules when
> >>>>built-in.
> >>>>
> >>>>This reverts the old work around implemented through commit
> >>>>1bacc894c227fad8a7 ("drivers: Move iommu/ before gpu/ in Makefile"),
> >>>>instead of making the dependency implicit by linker order this
> >>>>makes the ordering requirement explicit through proper kernel
> >>>>APIs.
> >>>>
> >>>>Cc: Oded Gabbay <oded.gabbay@xxxxxxx>
> >>>>Cc: Christian König <christian.koenig@xxxxxxx>
> >>>>Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
> >>
> >>Sorry for not responding earlier. Just coming back to all the stuff on my TODO list.
> >>
> >>Patch is Acked-by: Christian König <christian.koenig@xxxxxxx>
> >
> >Christian,
> >Just wanted to be sure if you tested this patch-set or not.
>
> I did NOT tested it. If AMD IOMMU requires something which will now
> initialize after the IOMMU module we will obviously run into trouble
> again.
>
> I assumed that the creator of the patch did some testing.

Nope, hence [RTF] Request For Testing.

> >I don't think it should be merged without testing. If you already
> >tested it than fine. If not, I think I can do it in the next week or
> >so (just came back from PTO).
>
> Yeah, agree totally.

Agreed, please let me know if someone is able to test and confirm
this works. It should work.

Luis