Hi Rob, On Friday 25 July 2014 07:45 PM, Rob Herring wrote: > On Fri, Jul 25, 2014 at 6:02 AM, Vineet Gupta > <Vineet.Gupta1@xxxxxxxxxxxx> wrote: >> > Hi Grant, >> > >> > linux-next has a series for arc_uart (via tty tree) which converts it to generic >> > earlycon and specifies console via /chosen/stdout-path vs. an explicit param in >> > /chose/bootargs >> > >> > 2014-06-24 9da433c0a0b5 ARC: [arcfpga] stdout-path now suffices for earlycon/console >> > >> > This relied on prev commit of yours (from linux next of 20140711), which seem to >> > have disappeared now. >> > >> > 2014-03-27 a9296cf2d0b6 of: Create of_console_check() for selecting a console >> > specified in /chosen >> > 2014-03-27 cfa9cacc5dd3 of: Enable console on serial ports specified by >> > /chosen/stdout-path >> > >> > Is there a specific reason for dropping these patches (or perhaps a merge to be >> > merged). I cherry-picked both but still doesn't work. >> > >> > Can you please advise next step forward, before I go off debugging with those >> > patches in. > There's an issue that if you have stdout-path and "earlycon" on the > command line, the kernel will switch to tty0 and disable the earlycon. > > This is the "fix", but I don't like adding the DT dependency into generic code: > > @@ -2382,7 +2386,7 @@ void register_console(struct console *newcon) > if (newcon->setup == NULL || > newcon->setup(newcon, NULL) == 0) { > newcon->flags |= CON_ENABLED; > - if (newcon->device) { > + if (newcon->device && !of_stdout) { > newcon->flags |= CON_CONSDEV; > preferred_console = 0; > } The DT settings relevant for ARC, which enable generic-earlycon and console-with-stdout-path are as follows chosen { bootargs = "earlycon"; stdout-path = &arcuart0; }; .... arcuart0: serial@c0fc1000 { compatible = "snps,arc-uart"; And it works w/o above hunk, provided the 2 patches from Grant exist in linux-next which they don't at the moment. I'm pretty confused how the hunk above comes into picture. And if not then I will have to get the ARC std-out patch reverted in tty-next as it is broken. Thx, -Vineet -- 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