72 lines
2.9 KiB
Diff
72 lines
2.9 KiB
Diff
From e13e4c41a1cb64f703b8a71a185c4e29fadac5fc Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Thu, 14 Sep 2023 20:43:30 +0206
|
|
Subject: [PATCH 039/196] serial: 8250_pci1xxxx: Use port lock wrappers
|
|
|
|
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.
|
|
|
|
To avoid adding this functionality to all UART drivers, wrap the
|
|
spin_[un]lock*() invocations for uart_port::lock into helper functions
|
|
which just contain the spin_[un]lock*() invocations for now. In a
|
|
subsequent step these helpers will gain the console synchronization
|
|
mechanisms.
|
|
|
|
Converted with coccinelle. No functional change.
|
|
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Signed-off-by: John Ogness <john.ogness@linutronix.de>
|
|
Link: https://lore.kernel.org/r/20230914183831.587273-14-john.ogness@linutronix.de
|
|
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
drivers/tty/serial/8250/8250_pci1xxxx.c | 8 ++++----
|
|
1 file changed, 4 insertions(+), 4 deletions(-)
|
|
|
|
diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
|
|
index a3b25779d921..53e238c8cc89 100644
|
|
--- a/drivers/tty/serial/8250/8250_pci1xxxx.c
|
|
+++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
|
|
@@ -225,10 +225,10 @@ static bool pci1xxxx_port_suspend(int line)
|
|
if (port->suspended == 0 && port->dev) {
|
|
wakeup_mask = readb(up->port.membase + UART_WAKE_MASK_REG);
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
port->mctrl &= ~TIOCM_OUT2;
|
|
port->ops->set_mctrl(port, port->mctrl);
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
|
|
ret = (wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS;
|
|
}
|
|
@@ -251,10 +251,10 @@ static void pci1xxxx_port_resume(int line)
|
|
writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
|
|
|
|
if (port->suspended == 0) {
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
port->mctrl |= TIOCM_OUT2;
|
|
port->ops->set_mctrl(port, port->mctrl);
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
mutex_unlock(&tport->mutex);
|
|
}
|
|
--
|
|
2.43.2
|
|
|