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 af21122dfadec..1d501154e9f78 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2585,6 +2585,7 @@ 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;