[PATCH 1/5] drm/msm: Remove pm_runtime operations from msm_iommu

[Jordan Crouse]

On Thu, Jun 14, 2018 at 12:30:35PM +0530, Vivek Gautam wrote:
> Hi Jordan,
> 
> On Mon, Jun 11, 2018 at 11:56 PM, Jordan Crouse <jcrouse at codeaurora.org> wrote:
> > Now that the IOMMU is the master of it's own power we don't need to bring
> > up the GPU to do IOMMU operations. This is good because bringing up a6xx
> > requires the GMU so calling pm_runtime_get_sync() too early in the process
> > gets us into some nasty circular dependency situations.
> 
> Thanks for the patch.
> While you are removing these calls, we should add pm_runtime calls
> to qcom_iommu_map(). That should make qcom_iommu too master of
> its power control.
> Then we should be good to go with this patch.

Right - I told Rob about that in IRC but I should have mentioned it here as
well. In order to do this we need to be sure that all of of the possible MMU
combinations are covered.

> >
> > Signed-off-by: Jordan Crouse <jcrouse at codeaurora.org>
> > ---
> >  drivers/gpu/drm/msm/msm_iommu.c | 8 --------
> >  1 file changed, 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> > index b23d33622f37..ccd93ac6a4d8 100644
> > --- a/drivers/gpu/drm/msm/msm_iommu.c
> > +++ b/drivers/gpu/drm/msm/msm_iommu.c
> > @@ -40,9 +40,7 @@ static int msm_iommu_attach(struct msm_mmu *mmu, const char * const *names,
> >         struct msm_iommu *iommu = to_msm_iommu(mmu);
> >         int ret;
> >
> > -       pm_runtime_get_sync(mmu->dev);
> >         ret = iommu_attach_device(iommu->domain, mmu->dev);
> > -       pm_runtime_put_sync(mmu->dev);
> 
> may be just do the following here.
>            return iommu_attach_device(iommu->domain, mmu->dev);

I'll do that. Thanks.

Jordan

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