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-rw-r--r--debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch146
1 files changed, 146 insertions, 0 deletions
diff --git a/debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..10ae6c477c
--- /dev/null
+++ b/debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch
@@ -0,0 +1,146 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:44:23 +0206
+Subject: [PATCH 066/134] serial: sunplus-uart: 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/20230914183831.587273-67-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/sunplus-uart.c | 26 +++++++++++++-------------
+ 1 file changed, 13 insertions(+), 13 deletions(-)
+
+--- a/drivers/tty/serial/sunplus-uart.c
++++ b/drivers/tty/serial/sunplus-uart.c
+@@ -184,7 +184,7 @@ static void sunplus_break_ctl(struct uar
+ unsigned long flags;
+ unsigned int lcr;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ lcr = readl(port->membase + SUP_UART_LCR);
+
+@@ -195,7 +195,7 @@ static void sunplus_break_ctl(struct uar
+
+ writel(lcr, port->membase + SUP_UART_LCR);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static void transmit_chars(struct uart_port *port)
+@@ -277,7 +277,7 @@ static irqreturn_t sunplus_uart_irq(int
+ struct uart_port *port = args;
+ unsigned int isc;
+
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+
+ isc = readl(port->membase + SUP_UART_ISC);
+
+@@ -287,7 +287,7 @@ static irqreturn_t sunplus_uart_irq(int
+ if (isc & SUP_UART_ISC_TX)
+ transmit_chars(port);
+
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ return IRQ_HANDLED;
+ }
+@@ -302,14 +302,14 @@ static int sunplus_startup(struct uart_p
+ if (ret)
+ return ret;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ /* isc define Bit[7:4] int setting, Bit[3:0] int status
+ * isc register will clean Bit[3:0] int status after read
+ * only do a write to Bit[7:4] int setting
+ */
+ isc |= SUP_UART_ISC_RXM;
+ writel(isc, port->membase + SUP_UART_ISC);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return 0;
+ }
+@@ -318,13 +318,13 @@ static void sunplus_shutdown(struct uart
+ {
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ /* isc define Bit[7:4] int setting, Bit[3:0] int status
+ * isc register will clean Bit[3:0] int status after read
+ * only do a write to Bit[7:4] int setting
+ */
+ writel(0, port->membase + SUP_UART_ISC); /* disable all interrupt */
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ free_irq(port->irq, port);
+ }
+@@ -372,7 +372,7 @@ static void sunplus_set_termios(struct u
+ lcr |= UART_LCR_EPAR;
+ }
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+@@ -407,7 +407,7 @@ static void sunplus_set_termios(struct u
+ writel(div_l, port->membase + SUP_UART_DIV_L);
+ writel(lcr, port->membase + SUP_UART_LCR);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static void sunplus_set_ldisc(struct uart_port *port, struct ktermios *termios)
+@@ -517,15 +517,15 @@ static void sunplus_console_write(struct
+ if (sunplus_console_ports[co->index]->port.sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+- locked = spin_trylock(&sunplus_console_ports[co->index]->port.lock);
++ locked = uart_port_trylock(&sunplus_console_ports[co->index]->port);
+ else
+- spin_lock(&sunplus_console_ports[co->index]->port.lock);
++ uart_port_lock(&sunplus_console_ports[co->index]->port);
+
+ uart_console_write(&sunplus_console_ports[co->index]->port, s, count,
+ sunplus_uart_console_putchar);
+
+ if (locked)
+- spin_unlock(&sunplus_console_ports[co->index]->port.lock);
++ uart_port_unlock(&sunplus_console_ports[co->index]->port);
+
+ local_irq_restore(flags);
+ }