android_kernel_motorola_sm6375/include
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Thomas Gleixner e8646f5d34 serial: core: Provide port lock wrappers
[ Upstream commit b0af4bcb49464c221ad5f95d40f2b1b252ceedcc ]

When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.

So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.

All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.

Provide wrapper functions for spin_[un]lock*(port->lock) invocations so
that the console mechanics can be applied later on at a single place and
does not require to copy the same logic all over the drivers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 54c4ec5f8c47 ("serial: mxs-auart: add spinlock around changing cts state")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-02 16:18:35 +02:00
..
acpi
asm-generic asm-generic: qspinlock: fix queued_spin_value_unlocked() implementation 2023-12-20 15:41:22 +01:00
clocksource
crypto crypto: af_alg - Disallow multiple in-flight AIO requests 2024-01-25 14:34:23 -08:00
drm drm: Don't treat 0 as -1 in drm_fixp2int_ceil 2024-03-26 18:22:19 -04:00
dt-bindings
keys
kvm
linux serial: core: Provide port lock wrappers 2024-05-02 16:18:35 +02:00
math-emu
media media: rename VFL_TYPE_GRABBER to _VIDEO 2024-03-26 18:22:22 -04:00
misc
net af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc(). 2024-05-02 16:18:35 +02:00
pcmcia
ras
rdma
scsi scsi: core: Introduce the scsi_cmd_to_rq() function 2023-12-08 08:44:28 +01:00
soc soc: fsl: qbman: Add CGR update function 2024-04-13 12:51:27 +02:00
sound
target
trace neighbor: tracing: Move pin6 inside CONFIG_IPV6=y section 2023-10-25 11:53:22 +02:00
uapi Input: allocate keycode for Display refresh rate toggle 2024-04-13 12:51:39 +02:00
vdso
video
xen