On 25/09/15 16:03, Arnd Bergmann wrote: > On Friday 25 September 2015 15:56:40 Jon Hunter wrote: >> + case DMA_MEM_TO_DEV: >> + burst_size = fls(tdc->config.dst_maxburst); >> + ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(num_bufs - 1); >> + ch_regs->ctrl = ADMA_CH_CTRL_XFER_DIR(ADMA_MEM_TO_AHUB) | >> + ADMA_CH_CTRL_TX_REQ(tdc->config.slave_id); >> + ch_regs->src_addr = buf_addr; >> + break; >> + >> + case DMA_DEV_TO_MEM: >> + burst_size = fls(tdc->config.src_maxburst); >> + ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(num_bufs - 1); >> + ch_regs->ctrl = ADMA_CH_CTRL_XFER_DIR(ADMA_AHUB_TO_MEM) | >> + ADMA_CH_CTRL_RX_REQ(tdc->config.slave_id); >> + ch_regs->trg_addr = buf_addr; >> + break; > > Do not use the 'slave_id' field here to identify the slave device, that > concept is broken. Instead, put the slave identification into the > dma specifier in DT and read it out in your xlate function. Why is it broken? What happens if I don't know the slave-id? In other words, the slave-id can be dynamically allocated and associated with a given slave. Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html