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-rw-r--r--debian/patches-rt/0071-serial-uartlite-Use-port-lock-wrappers.patch105
1 files changed, 105 insertions, 0 deletions
diff --git a/debian/patches-rt/0071-serial-uartlite-Use-port-lock-wrappers.patch b/debian/patches-rt/0071-serial-uartlite-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..13c64d7eed
--- /dev/null
+++ b/debian/patches-rt/0071-serial-uartlite-Use-port-lock-wrappers.patch
@@ -0,0 +1,105 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:44:28 +0206
+Subject: [PATCH 071/134] serial: uartlite: 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/20230914183831.587273-72-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/uartlite.c | 18 +++++++++---------
+ 1 file changed, 9 insertions(+), 9 deletions(-)
+
+--- a/drivers/tty/serial/uartlite.c
++++ b/drivers/tty/serial/uartlite.c
+@@ -216,11 +216,11 @@ static irqreturn_t ulite_isr(int irq, vo
+ unsigned long flags;
+
+ do {
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ stat = uart_in32(ULITE_STATUS, port);
+ busy = ulite_receive(port, stat);
+ busy |= ulite_transmit(port, stat);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ n++;
+ } while (busy);
+
+@@ -238,9 +238,9 @@ static unsigned int ulite_tx_empty(struc
+ unsigned long flags;
+ unsigned int ret;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ ret = uart_in32(ULITE_STATUS, port);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
+ }
+@@ -323,7 +323,7 @@ static void ulite_set_termios(struct uar
+ termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE);
+ tty_termios_encode_baud_rate(termios, pdata->baud, pdata->baud);
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
+ | ULITE_STATUS_TXFULL;
+@@ -346,7 +346,7 @@ static void ulite_set_termios(struct uar
+ /* update timeout */
+ uart_update_timeout(port, termios->c_cflag, pdata->baud);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static const char *ulite_type(struct uart_port *port)
+@@ -495,9 +495,9 @@ static void ulite_console_write(struct c
+ int locked = 1;
+
+ if (oops_in_progress) {
+- locked = spin_trylock_irqsave(&port->lock, flags);
++ locked = uart_port_trylock_irqsave(port, &flags);
+ } else
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* save and disable interrupt */
+ ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
+@@ -512,7 +512,7 @@ static void ulite_console_write(struct c
+ uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
+
+ if (locked)
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static int ulite_console_setup(struct console *co, char *options)