Messages in this thread | | | From | Alexander Duyck <> | Date | Thu, 4 Oct 2018 08:13:26 -0700 | Subject | Re: [PATCH] dma-direct: Fix return value of dma_direct_supported |
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On Thu, Oct 4, 2018 at 4:25 AM Robin Murphy <robin.murphy@arm.com> wrote: > > On 04/10/18 00:48, Alexander Duyck wrote: > > It appears that in commit 9d7a224b463e ("dma-direct: always allow dma mask > > <= physiscal memory size") the logic of the test was changed from a "<" to > > a ">=" however I don't see any reason for that change. I am assuming that > > there was some additional change planned, specifically I suspect the logic > > was intended to be reversed and possibly used for a return. Since that is > > the case I have gone ahead and done that. > > Bah, seems I got hung up on the min_mask code above it and totally > overlooked that the condition itself got flipped. It probably also can't > help that it's an int return type, but treated as a bool by callers > rather than "0 for success" as int tends to imply in isolation. > > Anyway, paying a bit more attention this time, I think this looks like > the right fix - cheers Alex. > > Robin.
Thanks for the review.
- Alex
P.S. It looks like I forgot to add Christoph to the original mail since I had just copied the To and Cc from the original submission, so I added him to the Cc for this.
> > This addresses issues I had on my system that prevented me from booting > > with the above mentioned commit applied on an x86_64 system w/ Intel IOMMU. > > > > Fixes: 9d7a224b463e ("dma-direct: always allow dma mask <= physiscal memory size") > > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> > > --- > > kernel/dma/direct.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > > index 5a0806b5351b..65872f6c2e93 100644 > > --- a/kernel/dma/direct.c > > +++ b/kernel/dma/direct.c > > @@ -301,9 +301,7 @@ int dma_direct_supported(struct device *dev, u64 mask) > > > > min_mask = min_t(u64, min_mask, (max_pfn - 1) << PAGE_SHIFT); > > > > - if (mask >= phys_to_dma(dev, min_mask)) > > - return 0; > > - return 1; > > + return mask >= phys_to_dma(dev, min_mask); > > } > > > > int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr) > > > > _______________________________________________ > > iommu mailing list > > iommu@lists.linux-foundation.org > > https://lists.linuxfoundation.org/mailman/listinfo/iommu > > > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu
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