[PATCH 5.1 106/128] tty: Dont force RISCV SBI console as preferred console

From: Greg Kroah-Hartman
Date: Mon May 20 2019 - 08:38:01 EST

From: Anup Patel <Anup.Patel@xxxxxxx>

commit f91253a3d005796404ae0e578b3394459b5f9b71 upstream.

The Linux kernel will auto-disables all boot consoles whenever it
gets a preferred real console.

Currently on RISC-V systems, if we have a real console which is not
RISCV SBI console then boot consoles (such as earlycon=sbi) are not
auto-disabled when a real console (ttyS0 or ttySIF0) is available.
This results in duplicate prints at boot-time after kernel starts
using real console (i.e. ttyS0 or ttySIF0) if "earlycon=" kernel
parameter was passed by bootloader.

The reason for above issue is that RISCV SBI console always adds
itself as preferred console which is causing other real consoles
to be not used as preferred console.

Ideally "console=" kernel parameter passed by bootloaders should
be the one selecting a preferred real console.

This patch fixes above issue by not forcing RISCV SBI console as
preferred console.

Fixes: afa6b1ccfad5 ("tty: New RISC-V SBI console driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
Reviewed-by: Atish Patra <atish.patra@xxxxxxx>
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/tty/hvc/hvc_riscv_sbi.c | 1 -
1 file changed, 1 deletion(-)

--- a/drivers/tty/hvc/hvc_riscv_sbi.c
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c
@@ -53,7 +53,6 @@ device_initcall(hvc_sbi_init);
static int __init hvc_sbi_console_init(void)
hvc_instantiate(0, 0, &hvc_sbi_ops);
- add_preferred_console("hvc", 0, NULL);

return 0;