On 28/04/20 19:40, John Stultz 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, 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. > Agreed with all of the above! Reviewed-and-tested-by: Valentin Schneider <valentin.schneider@xxxxxxx> Thanks to both of you, John & Andy. > Cc: Valentin Schneider <valentin.schneider@xxxxxxx> > Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Cc: Russell King <linux@xxxxxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Jiri Slaby <jslaby@xxxxxxxx> > Cc: linux-serial@xxxxxxxxxxxxxxx > Reported-by: Valentin Schneider <valentin.schneider@xxxxxxx> > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> > --- > v2: Added extra context in the commit message > --- > 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;
