Hi Russell! On 21 January 2015 at 23:01, Russell King - ARM Linux <li...@arm.linux.org.uk> wrote: > 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.
Thanks for your comments! I suppose in that case, I will leave out the *dma_masks from this constraints information for now; we can re-visit it when a specific use case really needs information about the dma-masks of the attached devices. I will post an updated patch-set soon. > > -- > FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up > according to speedtest.net. -- Thanks and regards, Sumit Semwal Kernel Team Lead - Linaro Mobile Group Linaro.org │ Open source software for ARM SoCs -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html