Re: [PATCH 2/4] drm/i915/gtt: Warn if the next layer scratch dma is invalid

Chris Wilson
2015-06-30T17:11:14Z

On Tue, Jun 30, 2015 at 05:59:27PM +0100, Michel Thierry wrote:
> On 6/30/2015 4:16 PM, Mika Kuoppala wrote:
> >When dma page is setup, warn if we try to point the entries
> >to a uninitialized (zero) dma address. Like we do with gen6

Just a note that 0 looks only to be reserved due to a quirk of the
intel-iommu implementation. There is nothing preventing a different
iommu or future implementation using 0 as a valid dma_addr_t afaict.

This should presumably be
WARN_ON(dma_mapping_error(&dev->pdev->dev, px_dma()));
-Chris

--
Chris Wilson, Intel Open Source Technology Centre