Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.9 36/80] serial: amba-pl011: Make sure we initialize the port.lock spinlock | Date | Wed, 17 Jun 2020 21:27:35 -0400 |
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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 f6586a8681b9..b3b9b3d2cddf 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2524,6 +2524,7 @@ 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
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