lkml.org 
[lkml]   [2020]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC][PATCH] serial: amba-pl011: Make sure we initialize the port.lock spinlock
On Fri, Apr 24, 2020 at 1:06 AM John Stultz <john.stultz@linaro.org> wrote:
>
> Valentine reported seeing:
>
> [ 3.626638] INFO: trying to register non-static key.
> [ 3.626639] the code is fine but needs lockdep annotation.
> [ 3.626640] turning off the locking correctness validator.
> [ 3.626644] CPU: 7 PID: 51 Comm: kworker/7:1 Not tainted 5.7.0-rc2-00115-g8c2e9790f196 #116
> [ 3.626646] Hardware name: HiKey960 (DT)
> [ 3.626656] Workqueue: events deferred_probe_work_func
> [ 3.632476] sd 0:0:0:0: [sda] Optimal transfer size 8192 bytes not a multiple of physical block size (16384 bytes)
> [ 3.640220] Call trace:
> [ 3.640225] dump_backtrace+0x0/0x1b8
> [ 3.640227] show_stack+0x20/0x30
> [ 3.640230] dump_stack+0xec/0x158
> [ 3.640234] register_lock_class+0x598/0x5c0
> [ 3.640235] __lock_acquire+0x80/0x16c0
> [ 3.640236] lock_acquire+0xf4/0x4a0
> [ 3.640241] _raw_spin_lock_irqsave+0x70/0xa8
> [ 3.640245] uart_add_one_port+0x388/0x4b8
> [ 3.640248] pl011_register_port+0x70/0xf0
> [ 3.640250] pl011_probe+0x184/0x1b8
> [ 3.640254] amba_probe+0xdc/0x180
> [ 3.640256] really_probe+0xe0/0x338
> [ 3.640257] driver_probe_device+0x60/0xf8
> [ 3.640259] __device_attach_driver+0x8c/0xd0
> [ 3.640260] bus_for_each_drv+0x84/0xd8
> [ 3.640261] __device_attach+0xe4/0x140
> [ 3.640263] device_initial_probe+0x1c/0x28
> [ 3.640265] bus_probe_device+0xa4/0xb0
> [ 3.640266] deferred_probe_work_func+0x7c/0xb8
> [ 3.640269] process_one_work+0x2c0/0x768
> [ 3.640271] worker_thread+0x4c/0x498
> [ 3.640272] kthread+0x14c/0x158
> [ 3.640275] ret_from_fork+0x10/0x1c
>
> Which seems to be due to the fact that after allocating the uap
> structure, the pl011 code doesn't initialize the spinlock.
>
> This patch fixes it by initializing the spinlock and the warning
> has gone away.
>

I think it's step to the right direction. FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> CC: Valentin Schneider <valentin.schneider@arm.com>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jslaby@suse.com>
> Cc: linux-serial@vger.kernel.org
> Reported-by: Valentin Schneider <valentin.schneider@arm.com>
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> drivers/tty/serial/amba-pl011.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 2296bb0f9578..458fc3d9d48c 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2575,6 +2575,7 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
> uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
> uap->port.flags = UPF_BOOT_AUTOCONF;
> uap->port.line = index;
> + spin_lock_init(&uap->port.lock);
>
> amba_ports[index] = uap;
>
> --
> 2.17.1
>


--
With Best Regards,
Andy Shevchenko

\
 
 \ /
  Last update: 2020-04-27 11:06    [W:0.131 / U:23.932 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site