Re: [PATCH 2/4] drm/vmwgfx: remove CONFIG_INTEL_IOMMU ifdefs v2

From: Thomas Hellstrom
Date: Tue Feb 05 2019 - 02:59:33 EST


On Mon, 2019-02-04 at 13:11 +0100, Thomas HellstrÃm wrote:
> On Mon, 2019-02-04 at 09:19 +0100, Christoph Hellwig wrote:
> > On Fri, Jan 25, 2019 at 09:12:13AM +0100, Thomas Hellstrom wrote:
> > > -#if !defined(CONFIG_SWIOTLB) && !defined(CONFIG_INTEL_IOMMU)
> > > - /*
> > > - * No coherent page pool
> > > - */
> > > - if (dev_priv->map_mode == vmw_dma_alloc_coherent)
> > > + /* No TTM coherent page pool? FIXME: Ask TTM instead! */
> > > + if (!(IS_ENABLED(CONFIG_SWIOTLB) ||
> > > IS_ENABLED(CONFIG_INTEL_IOMMU)) &&
> > > + (dev_priv->map_mode == vmw_dma_alloc_coherent))
> > > return -EINVAL;
> > > -#endif
> > > +
> >
> > I don't think this edited in change makes any sense. The swiotlb
> > vs
> > dma-direct versions of dma_alloc_coherent are the same, so this
> > check
> > seems very obsfucating.
>
> So this part of code is identical in functionality to the previous
> version. It checks whether the TTM module has the coherent page pool
> enabled. (an identical test is present in TTM). What we *really* need
> to do here instead is to ask TTM whether it has enabled its coherent
> page pool instead of trying to mimic TTM's test, and I have a
> changeset
> under review for that. But as mentioned previously, I don't want to
> change the TTM interface outside of a merge window, so we either have
> to live with the above for 5.0 or keep the old defines. I'd prefer
> the
> former so I don't have to respin the patch series once more.
>
> Thanks,
> Thoams
>

Hi, Christoph,

I need to get this merged this week. Could you please ack or ack
removing this hunk + updating the following patches for merge errors?

If no response, I'll add a Cc: tag on the patch and a #v1 to your s-o-
b.

Thanks,
Thomas