Hi Waldemar, On Fri, May 16, 2014 at 3:49 PM, Waldemar Brodkorb <wbx@xxxxxxxxxxx> wrote: > I am trying to bootup my Mikrotik RB532 board with the latest > kernel, but my serial console is disabled after boot: > .. > Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled > serial8250: ttyS0 at MMIO 0x0 (irq = 104, base_baud = 12499875) is a > 16550A > console [ttyS0] enabled > console [ttyS0] disabled > > I used git bisect to find the problematic commit: > commit 5f5c9ae56c38942623f69c3e6dc6ec78e4da2076 > Author: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx> > Date: Fri Feb 28 14:21:32 2014 +0100 > > serial_core: Unregister console in uart_remove_one_port() > > If the serial port being removed is used as a console, it must > also be > unregistered from the console subsystem using > unregister_console(). > > uart_ops.release_port() will release resources (e.g. iounmap() > the serial > port registers), causing a crash on subsequent kernel output if > the console > is still registered. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > After reverting the change, everything is fine. Does this patch help? https://lkml.org/lkml/2014/5/10/9 I guess you're not using of_serial? Your serial driver may need to set port.type too, if it doesn't already do so and the type is PORT_UNKNOWN on re-registration. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
