| From 23cd5a0ff4a372b0f248e2a43f3096402095b9f1 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 28 Apr 2020 18:40:50 +0000 |
| Subject: serial: amba-pl011: Make sure we initialize the port.lock spinlock |
| |
| From: John Stultz <john.stultz@linaro.org> |
| |
| [ Upstream commit 8508f4cba308f785b2fd4b8c38849c117b407297 ] |
| |
| 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, nothing initializes the spinlock. |
| |
| Its a little confusing, as uart_port_spin_lock_init() is one |
| place where the lock is supposed to be initialized, but it has |
| an exception for the case where the port is a console. |
| |
| This makes it seem like a deeper fix is needed to properly |
| register the console, but I'm not sure what that entails, and |
| Andy suggested that this approach is less invasive. |
| |
| Thus, this patch resolves the issue by initializing the spinlock |
| in the driver, and resolves the resulting warning. |
| |
| Cc: Andy Shevchenko <andy.shevchenko@gmail.com> |
| Cc: Russell King <linux@armlinux.org.uk> |
| Cc: Jiri Slaby <jslaby@suse.com> |
| Cc: linux-serial@vger.kernel.org |
| Reported-by: Valentin Schneider <valentin.schneider@arm.com> |
| Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> |
| Signed-off-by: John Stultz <john.stultz@linaro.org> |
| Reviewed-and-tested-by: Valentin Schneider <valentin.schneider@arm.com> |
| Link: https://lore.kernel.org/r/20200428184050.6501-1-john.stultz@linaro.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.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 637f72fb6427f..e55b556337214 100644 |
| --- a/drivers/tty/serial/amba-pl011.c |
| +++ b/drivers/tty/serial/amba-pl011.c |
| @@ -2605,6 +2605,7 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap, |
| uap->port.fifosize = uap->fifosize; |
| uap->port.flags = UPF_BOOT_AUTOCONF; |
| uap->port.line = index; |
| + spin_lock_init(&uap->port.lock); |
| |
| amba_ports[index] = uap; |
| |
| -- |
| 2.25.1 |
| |