On Tue, 25 Nov 2014 00:00:16 +0100 , Andrew Lunn <andrew@xxxxxxx> wrote: > On Mon, Nov 24, 2014 at 10:23:58PM +0000, Leif Lindholm wrote: > > Support specifying console options (like with console=ttyXN,<options>) > > by appending them to the stdout-path property after a separating ':'. > > > > Example: > > stdout-path = "uart0:115200"; > > > > This patch also modifies of_find_node_by_path() to match only the > > portion of the path before a ':'. > > Hi Leif > > These appears to somewhat conform to ePAPR, which says: > > A string that specifies the full path to the node representing > the device to be used for boot console output. If the character > ":" is present in the value it terminates the path. > > So you can put any random junk after the :. However, are we going to > have backward/forward compatibility problems, and problems with > bootloaders? The current kernel code does not look for the :. So a new > DT blob on an old kernel will not work so well. For DT, we've generally not been worrying about compatibility in that direction. If we've got a new firmware, we should be able to get a new kernel. Nobody has really screamed bout it yet. > More worrying, barebox does not support the : either. So there is a > danger your bootloader suddenly goes silent after a dt blob update. Is barebox parsing the property? Or updating it? Or both? I've got no problem with this patch, but we can also support things like the 'current-speed' property in the UART to set a default when the stdout path doesn't have any arguments. g. -- 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
