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authorJohn Stultz <john.stultz@linaro.org>2020-04-28 18:40:50 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-06-17 16:43:05 +0200
commiteaffdc4cebe4ba45976481953249a35db75eb3ea (patch)
tree5367553d6daa8d489b49800a4cd3e351a4f7484d
parentdafcfb953d95c85e035117cb3455fc78e7e3fb4c (diff)
serial: amba-pl011: Make sure we initialize the port.lock spinlock
commit 8508f4cba308f785b2fd4b8c38849c117b407297 upstream. 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 Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/amba-pl011.c1
1 files changed, 1 insertions, 0 deletions
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;