From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
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.rj@xxxxxxxxxxxxxx>
Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1593618100-2151-1-git-send-email-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
