On Tue, Oct 28, 2014 at 12:44:31AM +0100, Piotr Król wrote: > Hi all, > according to BCM2835 ARM Peripherals spec DMA is optional functionality > for ARM PL011 UART and it is not supported on this SoC. It looks like > amba-pl011 search for device tree property (dma-names) unconditionally, > what leads to error message: > > of_dma_request_slave_channel: dma-names property of node '/soc/uart@7e201000' missing or empty > uart-pl011 20201000.uart: no DMA platform data > > I assume that if it is possible that amba-pl011 can be without DMA we > should check if DMA is supported and then try to read properties. Is > there any known method for checking dma support ? If yes that I would be > glad for any pointers. > > Let me know if I should ignore/accept this error message or there is > some code fix needed. A great many implementations of PL011 do not have DMA support (some have DMA support but its well broken.) The driver has always supported PIO mode, and continues to do so. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
