Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

serial: sh-sci: Initialize spinlock for uart console

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

authored by

Lad Prabhakar and committed by
Greg Kroah-Hartman
f38278e9 76ed2e10

+3
+3
drivers/tty/serial/sh-sci.c
··· 3301 3301 sciport->port.flags |= UPF_HARD_FLOW; 3302 3302 } 3303 3303 3304 + if (sci_uart_driver.cons->index == sciport->port.line) 3305 + spin_lock_init(&sciport->port.lock); 3306 + 3304 3307 ret = uart_add_one_port(&sci_uart_driver, &sciport->port); 3305 3308 if (ret) { 3306 3309 sci_cleanup_single(sciport);