Re: ehci-pci breakage with dma-mapping changes in 5.4-rc2

From: Christoph Hellwig
Date: Mon Oct 07 2019 - 14:47:59 EST


On Mon, Oct 07, 2019 at 02:32:07PM -0400, Arvind Sankar wrote:
> On Mon, Oct 07, 2019 at 01:58:57PM -0400, Arvind Sankar wrote:
> > On Mon, Oct 07, 2019 at 10:56:30AM -0700, Christoph Hellwig wrote:
> > > On Mon, Oct 07, 2019 at 07:55:28PM +0200, Christoph Hellwig wrote:
> > > > On Mon, Oct 07, 2019 at 01:54:32PM -0400, Arvind Sankar wrote:
> > > > > It doesn't boot with the patch. Won't it go
> > > > > dma_get_required_mask
> > > > > -> intel_get_required_mask
> > > > > -> iommu_need_mapping
> > > > > -> dma_get_required_mask
> > > > > ?
> > > > >
> > > > > Should the call to dma_get_required_mask in iommu_need_mapping be
> > > > > replaced with dma_direct_get_required_mask on top of your patch?
> > > >
> > > > Yes, sorry.
> > >
> > > Actually my patch already calls dma_direct_get_required_mask.
> > > How did you get the loop?
> >
> > The function iommu_need_mapping (not changed by your patch) calls
> > dma_get_required_mask internally, to check whether the device's dma_mask
> > is big enough or not. That's the call I was asking whether it needs to
> > be changed.
>
> Yeah the attached patch seems to fix it.

That looks fine to me:

Acked-by: Christoph Hellwig <hch@xxxxxx>