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-rw-r--r--debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch127
1 files changed, 127 insertions, 0 deletions
diff --git a/debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch b/debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..966618a3e4
--- /dev/null
+++ b/debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch
@@ -0,0 +1,127 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:52 +0206
+Subject: [PATCH 035/134] serial: mcf: 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/20230914183831.587273-36-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/mcf.c | 20 ++++++++++----------
+ 1 file changed, 10 insertions(+), 10 deletions(-)
+
+--- a/drivers/tty/serial/mcf.c
++++ b/drivers/tty/serial/mcf.c
+@@ -135,12 +135,12 @@ static void mcf_break_ctl(struct uart_po
+ {
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ if (break_state == -1)
+ writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
+ else
+ writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /****************************************************************************/
+@@ -150,7 +150,7 @@ static int mcf_startup(struct uart_port
+ struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Reset UART, get it into known state... */
+ writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+@@ -164,7 +164,7 @@ static int mcf_startup(struct uart_port
+ pp->imr = MCFUART_UIR_RXREADY;
+ writeb(pp->imr, port->membase + MCFUART_UIMR);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return 0;
+ }
+@@ -176,7 +176,7 @@ static void mcf_shutdown(struct uart_por
+ struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Disable all interrupts now */
+ pp->imr = 0;
+@@ -186,7 +186,7 @@ static void mcf_shutdown(struct uart_por
+ writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+ writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /****************************************************************************/
+@@ -252,7 +252,7 @@ static void mcf_set_termios(struct uart_
+ mr2 |= MCFUART_MR2_TXCTS;
+ }
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ if (port->rs485.flags & SER_RS485_ENABLED) {
+ dev_dbg(port->dev, "Setting UART to RS485\n");
+ mr2 |= MCFUART_MR2_TXRTS;
+@@ -273,7 +273,7 @@ static void mcf_set_termios(struct uart_
+ port->membase + MCFUART_UCSR);
+ writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
+ port->membase + MCFUART_UCR);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /****************************************************************************/
+@@ -350,7 +350,7 @@ static irqreturn_t mcf_interrupt(int irq
+
+ isr = readb(port->membase + MCFUART_UISR) & pp->imr;
+
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ if (isr & MCFUART_UIR_RXREADY) {
+ mcf_rx_chars(pp);
+ ret = IRQ_HANDLED;
+@@ -359,7 +359,7 @@ static irqreturn_t mcf_interrupt(int irq
+ mcf_tx_chars(pp);
+ ret = IRQ_HANDLED;
+ }
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ return ret;
+ }