On Thu, Aug 01, 2019 at 10:35:02AM +0200, Lucas Stach wrote:
> Hi Christoph,
>
> Am Donnerstag, den 01.08.2019, 09:29 +0200 schrieb Christoph Hellwig:
> > Hi Lukas,
> >
> > have you tried the latest 5.3-rc kernel, where we limited the NVMe
> > I/O size based on the swiotlb buffer size?
>
> Yes, the issue was reproduced on 5.3-rc2. I now see your commit
> limiting the request size, so I guess I need to dig in to see why I'm
> still getting requests larger than the SWIOTLB max segment size. Thanks
> for the pointer!
a similar setup to yours the
dma_addressing_limited doesn't work, but if we changed it to a <=
it does. The result is counter to what I'd expect, but because I'm on
vacation I didn't have time to look into why it works. This is his
patch, let me know if this works for you:
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f7d1eea32c78..89ac1cf754cc 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -689,7 +689,7 @@ static inline int dma_coerce_mask_and_coherent(struct
device *dev, u64 mask)
*/
static inline bool dma_addressing_limited(struct device *dev)
{
- return min_not_zero(dma_get_mask(dev), dev->bus_dma_mask) <
+ return min_not_zero(dma_get_mask(dev), dev->bus_dma_mask) <=
dma_get_required_mask(dev);
}
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
