Messages in this thread | | | Date | Wed, 21 Jan 2015 17:31:28 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [RFCv2 2/2] dma-buf: add helpers for sharing attacher constraints with dma-parms |
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On Wed, Jan 21, 2015 at 09:46:47AM +0530, Sumit Semwal wrote: > +static int calc_constraints(struct device *dev, > + struct dma_buf_constraints *calc_cons) > +{ > + struct dma_buf_constraints cons = *calc_cons; > + > + cons.dma_mask &= dma_get_mask(dev);
I don't think this makes much sense when you consider that the DMA infrastructure supports buses with offsets. The DMA mask is th upper limit of the _bus_ specific address, it is not a mask per-se.
What this means is that &= is not the right operation. Moreover, simply comparing masks which could be from devices on unrelated buses doesn't make sense either.
However, that said, I don't have an answer for what you want to achieve here.
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