From: Lad Prabhakar <prabhakar.mahadev-lad...@bp.renesas.com>

commit f38278e9b810b06aff2981d505267be984423ba3 upstream.

serial core expects the spinlock to be initialized by the controller
driver for serial console, this patch makes sure the spinlock is
initialized, fixing the below issue:

[    0.865928] BUG: spinlock bad magic on CPU#0, swapper/0/1
[    0.865945]  lock: sci_ports+0x0/0x4c80, .magic: 00000000, .owner: 
<none>/-1, .owner_cpu: 0
[    0.865955] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1+ #112
[    0.865961] Hardware name: HopeRun HiHope RZ/G2H with sub board (DT)
[    0.865968] Call trace:
[    0.865979]  dump_backtrace+0x0/0x1d8
[    0.865985]  show_stack+0x14/0x20
[    0.865996]  dump_stack+0xe8/0x130
[    0.866006]  spin_dump+0x6c/0x88
[    0.866012]  do_raw_spin_lock+0xb0/0xf8
[    0.866023]  _raw_spin_lock_irqsave+0x80/0xa0
[    0.866032]  uart_add_one_port+0x3a4/0x4e0
[    0.866039]  sci_probe+0x504/0x7c8
[    0.866048]  platform_drv_probe+0x50/0xa0
[    0.866059]  really_probe+0xdc/0x330
[    0.866066]  driver_probe_device+0x58/0xb8
[    0.866072]  device_driver_attach+0x6c/0x90
[    0.866078]  __driver_attach+0x88/0xd0
[    0.866085]  bus_for_each_dev+0x74/0xc8
[    0.866091]  driver_attach+0x20/0x28
[    0.866098]  bus_add_driver+0x14c/0x1f8
[    0.866104]  driver_register+0x60/0x110
[    0.866109]  __platform_driver_register+0x40/0x48
[    0.866119]  sci_init+0x2c/0x34
[    0.866127]  do_one_initcall+0x88/0x428
[    0.866137]  kernel_init_freeable+0x2c0/0x328
[    0.866143]  kernel_init+0x10/0x108
[    0.866150]  ret_from_fork+0x10/0x18

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad...@bp.renesas.com>
Reviewed-by: Biju Das <biju.das...@bp.renesas.com>
Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for 
console")
Cc: stable <sta...@vger.kernel.org>
Link: 
https://lore.kernel.org/r/1593618100-2151-1-git-send-email-prabhakar.mahadev-lad...@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/tty/serial/sh-sci.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -3301,6 +3301,9 @@ static int sci_probe_single(struct platf
                sciport->port.flags |= UPF_HARD_FLOW;
        }
 
+       if (sci_uart_driver.cons->index == sciport->port.line)
+               spin_lock_init(&sciport->port.lock);
+
        ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
        if (ret) {
                sci_cleanup_single(sciport);


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