On Mon 2019-11-18 13:38:04, Jonathan Richardson wrote:
> On Thu, Nov 14, 2019 at 8:33 PM Sergey Senozhatsky
> <sergey.senozhatsky.work@xxxxxxxxx> wrote:
> >
> > Gosh, that part of printk is really complex.
> >
> > On (19/11/14 10:57), Petr Mladek wrote:
> > > For a proper solution we would need to match boot and real
> > > consoles that write messages into the physical device.
> > > But I am afraid that there is no support for this.
> >
> > Wouldn't those have same tty driver?
Interesting idea. Well, do early consoles have tty driver?
> > ---
> >
> > kernel/printk/printk.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> > index f1b08015d3fa..a84cb20acf42 100644
> > --- a/kernel/printk/printk.c
> > +++ b/kernel/printk/printk.c
> > @@ -2690,6 +2690,19 @@ static int __init keep_bootcon_setup(char *str)
> >
> > early_param("keep_bootcon", keep_bootcon_setup);
> >
> > +static bool known_console_driver(struct console *newcon)
> > +{
> > + struct console *con;
> > +
> > + for_each_console(con) {
> > + if (!(con->flags & CON_ENABLED))
> > + continue;
> > + if (con->device && con->device == newcon->device)
> > + return true;
> > + }
> > + return false;
> > +}
> > +
> > /*
> > * The console driver calls this routine during kernel initialization
> > * to register the console printing procedure with printk() and to
> > @@ -2828,6 +2841,9 @@ void register_console(struct console *newcon)
> > if (newcon->flags & CON_EXTENDED)
> > nr_ext_console_drivers++;
> >
> > + if (known_console_driver(newcon))
> > + newcon->flags &= ~CON_PRINTBUFFER;
> > +
> > if (newcon->flags & CON_PRINTBUFFER) {
> > /*
> > * console_unlock(); will print out the buffered messages
>
> Thanks.
Jonathan, have you tried this patch, please?
Does it solve your problem?
Best Regards,
Petr
