linux/drivers/tty
John Stultz 8508f4cba3 serial: amba-pl011: Make sure we initialize the port.lock spinlock
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>
2020-05-05 16:24:22 +02:00
..
hvc tty: hvc: Fix data abort due to race in hvc_open 2020-04-28 14:38:55 +02:00
ipwireless tty: add SPDX identifiers to Kconfig and Makefiles 2019-04-04 18:48:43 +02:00
serdev serdev: Fix detection of UART devices on Apple machines. 2020-03-06 14:10:44 +01:00
serial serial: amba-pl011: Make sure we initialize the port.lock spinlock 2020-05-05 16:24:22 +02:00
vt Merge 5.7-rc3 into tty-next 2020-04-27 09:33:21 +02:00
amiserial.c Remove every trace of SERIAL_MAGIC 2019-11-13 19:01:14 +08:00
cyclades.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
ehv_bytechan.c tty: evh_bytechan: Fix out of bounds accesses 2020-03-17 23:40:31 +11:00
goldfish.c
isicom.c tty/isicom: remove redundant assignment to variable word_count 2019-09-04 12:43:44 +02:00
Kconfig tty: reorganize tty & serial menus 2020-03-12 17:17:30 +01:00
Makefile tty: Add NULL TTY driver 2019-04-16 15:21:34 +02:00
mips_ejtag_fdc.c tty: mips_ejtag_fdc: Mark expected switch fall-through 2020-03-07 09:52:02 +01:00
moxa.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
moxa.h
mxser.c
mxser.h
n_gsm.c n_gsm: switch escape to bool 2020-02-19 12:46:48 +01:00
n_hdlc.c tty: n_hdlc, remove FILE and LINE from pr_debug 2020-03-16 08:39:47 +01:00
n_null.c
n_r3964.c
n_tracerouter.c
n_tracesink.c
n_tracesink.h tty: n_tracesink: Use the correct style for SPDX License Identifier 2020-03-18 13:01:31 +01:00
n_tty.c n_tty: Distribute switch variables for initialization 2020-02-23 20:14:50 +01:00
nozomi.c tty: nozomi: Use scnprintf() for avoiding potential buffer overflow 2020-03-18 12:59:29 +01:00
pty.c Revert "tty: pty: Fix race condition between release_one_tty and pty_write" 2019-03-29 15:47:40 +01:00
rocket_int.h
rocket.c Merge 5.7-rc3 into tty-next 2020-04-27 09:33:21 +02:00
rocket.h tty: rocket: Remove RCPK_GET_STRUCT ioctl 2019-04-25 11:58:56 +02:00
synclink_gt.c TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
synclink.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
synclinkmp.c TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
sysrq.c tty/sysrq: Export sysrq_mask(), sysrq_toggle_support() 2020-04-20 19:37:42 +02:00
tty_audit.c
tty_baudrate.c tty: baudrate: SPARC supports few more baud rates 2020-01-22 10:23:26 +01:00
tty_buffer.c
tty_io.c tty: fix compat TIOCGSERIAL checking wrong function ptr 2020-03-18 13:15:13 +01:00
tty_ioctl.c
tty_jobctrl.c tty: fix read of tty->pgrp outside of ctrl_lock 2019-03-28 01:28:23 +09:00
tty_ldisc.c tty_ldisc: simplify tty_ldisc_autoload initialization 2019-10-04 15:11:25 +02:00
tty_ldsem.c locking/lockdep: Remove unused @nested argument from lock_release() 2019-10-09 12:46:10 +02:00
tty_mutex.c
tty_port.c serdev: ttyport: restore client ops on deregistration 2020-02-10 12:26:44 -08:00
ttynull.c tty: Add NULL TTY driver 2019-04-16 15:21:34 +02:00
vcc.c sparc64: vcc: Fix error return code in vcc_probe() 2020-04-28 14:38:54 +02:00