On Tue, Jun 10, 2014 at 09:15:14PM +0200, Arnd Bergmann wrote: > On Tue, May 27, 2014 at 10:35:36AM +0200, Ludovic Desroches wrote: > > +static struct dma_chan *at_xdmac_xlate(struct of_phandle_args *dma_spec, > > + struct of_dma *of_dma) > > +{ > > + struct at_xdmac_chan *atchan; > > + struct dma_chan *chan; > > + dma_cap_mask_t mask; > > + struct platform_device *pdev = of_find_device_by_node(dma_spec->np); > > No need to search through all the device nodes, you can look up the > device from of_dma->of_dma_data. Thanks for the tip. > > > + if (dma_spec->args_count != 2) { > > + dev_err(&pdev->dev, "dma phandler args: bad number of args\n"); > > + return NULL; > > + } > > + > > + dma_cap_zero(mask); > > + dma_cap_set(DMA_SLAVE, mask); > > + chan = dma_request_channel(mask, NULL, NULL); > > + if (!chan) { > > + dev_err(&pdev->dev, "can't get a dma channel\n"); > > + return NULL; > > + } > > You must use dma_get_any_slave_channel. dma_request_channel gives you a > channel from a random dma engine that is present in the system, not > necessarily the one you are managing here. It is planned to use dma_get_any_slave_channel but currently I am doing tests on a 3.10 kernel that's why I am still using dma_request_channel. > > Arnd > -- > To unsubscribe from this list: send the line "unsubscribe dmaengine" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html