On Sat, 2017-08-26 at 02:44 +0900, Sergey Senozhatsky wrote: > On (08/25/17 16:14), Eugeniy Paltsev wrote: > > In the current implementation we take the first console that > > registers if we didn't select one. > > > > But if we specify console via "stdout-path" property in device tree > > we don't want first console that registers here to be selected. > > Otherwise we may choose wrong console - for example if some console > > is registered earlier than console is pointed in "stdout-path" > > property because console pointed in "stdout-path" property can be > > add as > > preferred quite late - when it's driver is probed. > > > > Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com> > > hm... this is not the first time we see DT and stdout-path. > and so far it was pretty painful :) e.g. commits c6c7d83b9c9e, > 05fd007e4629. > > -ss Hm... looks like I had to update my patch to keep existing tty0 behavior. Before this patch tty0 was registered even if it was specified neither in "bootargs" nor in "stdout-path".? So I should retain this behavior as a lot of ARM boards (and some powerpc) rely on it. > > > --- > > ?kernel/printk/printk.c | 11 +++++++++++ > > ?1 file changed, 11 insertions(+) > > > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > > index 512f7c2..23262c1 100644 > > --- a/kernel/printk/printk.c > > +++ b/kernel/printk/printk.c > > @@ -26,6 +26,7 @@ > > ?#include <linux/nmi.h> > > ?#include <linux/module.h> > > ?#include <linux/moduleparam.h> > > +#include <linux/of.h> > > ?#include <linux/delay.h> > > ?#include <linux/smp.h> > > ?#include <linux/security.h> > > @@ -2431,6 +2432,16 @@ void register_console(struct console > > *newcon) > > ? if (!has_preferred || bcon || !console_drivers) > > ? has_preferred = preferred_console >= 0; > > ? > > + > > + /* > > + ?* If we specify console via "stdout-path" property in > > device tree > > + ?* we don't want first console that registers here to be > > selected. > > + ?*/ > > +#ifdef CONFIG_OF > > + if (of_stdout) > > + has_preferred = true; > > +#endif > > + > > ? /* > > ? ?* See if we want to use this console driver. If we > > ? ?* didn't select a console we take the first one > > --? > > 2.9.3 > > -- ?Eugeniy Paltsev
