119 lines
4.1 KiB
Diff
119 lines
4.1 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Thu, 14 Sep 2023 20:43:38 +0206
|
|
Subject: [PATCH 021/134] serial: atmel: Use port lock wrappers
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz
|
|
|
|
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/20230914183831.587273-22-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/atmel_serial.c | 24 ++++++++++++------------
|
|
1 file changed, 12 insertions(+), 12 deletions(-)
|
|
|
|
--- a/drivers/tty/serial/atmel_serial.c
|
|
+++ b/drivers/tty/serial/atmel_serial.c
|
|
@@ -861,7 +861,7 @@ static void atmel_complete_tx_dma(void *
|
|
struct dma_chan *chan = atmel_port->chan_tx;
|
|
unsigned long flags;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
if (chan)
|
|
dmaengine_terminate_all(chan);
|
|
@@ -893,7 +893,7 @@ static void atmel_complete_tx_dma(void *
|
|
atmel_port->tx_done_mask);
|
|
}
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static void atmel_release_tx_dma(struct uart_port *port)
|
|
@@ -1711,9 +1711,9 @@ static void atmel_tasklet_rx_func(struct
|
|
struct uart_port *port = &atmel_port->uart;
|
|
|
|
/* The interrupt handler does not take the lock */
|
|
- spin_lock(&port->lock);
|
|
+ uart_port_lock(port);
|
|
atmel_port->schedule_rx(port);
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
}
|
|
|
|
static void atmel_tasklet_tx_func(struct tasklet_struct *t)
|
|
@@ -1723,9 +1723,9 @@ static void atmel_tasklet_tx_func(struct
|
|
struct uart_port *port = &atmel_port->uart;
|
|
|
|
/* The interrupt handler does not take the lock */
|
|
- spin_lock(&port->lock);
|
|
+ uart_port_lock(port);
|
|
atmel_port->schedule_tx(port);
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
}
|
|
|
|
static void atmel_init_property(struct atmel_uart_port *atmel_port,
|
|
@@ -2175,7 +2175,7 @@ static void atmel_set_termios(struct uar
|
|
} else
|
|
mode |= ATMEL_US_PAR_NONE;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
port->read_status_mask = ATMEL_US_OVRE;
|
|
if (termios->c_iflag & INPCK)
|
|
@@ -2377,22 +2377,22 @@ static void atmel_set_termios(struct uar
|
|
else
|
|
atmel_disable_ms(port);
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static void atmel_set_ldisc(struct uart_port *port, struct ktermios *termios)
|
|
{
|
|
if (termios->c_line == N_PPS) {
|
|
port->flags |= UPF_HARDPPS_CD;
|
|
- spin_lock_irq(&port->lock);
|
|
+ uart_port_lock_irq(port);
|
|
atmel_enable_ms(port);
|
|
- spin_unlock_irq(&port->lock);
|
|
+ uart_port_unlock_irq(port);
|
|
} else {
|
|
port->flags &= ~UPF_HARDPPS_CD;
|
|
if (!UART_ENABLE_MS(port, termios->c_cflag)) {
|
|
- spin_lock_irq(&port->lock);
|
|
+ uart_port_lock_irq(port);
|
|
atmel_disable_ms(port);
|
|
- spin_unlock_irq(&port->lock);
|
|
+ uart_port_unlock_irq(port);
|
|
}
|
|
}
|
|
}
|