Hi Greg,
-----Original Message----- From: gregkh@linuxfoundation.org gregkh@linuxfoundation.org Sent: 03 July 2020 09:41 To: Prabhakar Mahadev Lad prabhakar.mahadev-lad.rj@bp.renesas.com; Biju Das biju.das.jz@bp.renesas.com; gregkh@linuxfoundation.org; stable@vger.kernel.org Subject: patch "serial: sh-sci: Initialize spinlock for uart console" added to tty-linus
This is a note to let you know that I've just added the patch titled
serial: sh-sci: Initialize spinlock for uart consoleto my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
It looks like it's a regression in serial_core.c [1] as Geert pointed out [2]. Please drop this patch until we come to a conclusion.
[1] https://www.spinics.net/lists/linux-serial/msg37119.html [2] https://patchwork.kernel.org/patch/11636731/
Cheers, --Prabhakar
From f38278e9b810b06aff2981d505267be984423ba3 Mon Sep 17 00:00:00 2001 From: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Date: Wed, 1 Jul 2020 16:41:40 +0100 Subject: 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... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
drivers/tty/serial/sh-sci.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index e1179e74a2b8..204bb68ce3ca 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -3301,6 +3301,9 @@ static int sci_probe_single(struct platform_device *dev, 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); -- 2.27.0
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