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-rw-r--r--debian/patches-rt/0034-serial-ma35d1-Use-port-lock-wrappers.patch117
1 files changed, 117 insertions, 0 deletions
diff --git a/debian/patches-rt/0034-serial-ma35d1-Use-port-lock-wrappers.patch b/debian/patches-rt/0034-serial-ma35d1-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..995bad9aad
--- /dev/null
+++ b/debian/patches-rt/0034-serial-ma35d1-Use-port-lock-wrappers.patch
@@ -0,0 +1,117 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:51 +0206
+Subject: [PATCH 034/134] serial: ma35d1: 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/20230914183831.587273-35-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/ma35d1_serial.c | 22 +++++++++++-----------
+ 1 file changed, 11 insertions(+), 11 deletions(-)
+
+--- a/drivers/tty/serial/ma35d1_serial.c
++++ b/drivers/tty/serial/ma35d1_serial.c
+@@ -269,16 +269,16 @@ static void receive_chars(struct uart_ma
+ if (uart_handle_sysrq_char(&up->port, ch))
+ continue;
+
+- spin_lock(&up->port.lock);
++ uart_port_lock(&up->port);
+ uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
+- spin_unlock(&up->port.lock);
++ uart_port_unlock(&up->port);
+
+ fsr = serial_in(up, MA35_FSR_REG);
+ } while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
+
+- spin_lock(&up->port.lock);
++ uart_port_lock(&up->port);
+ tty_flip_buffer_push(&up->port.state->port);
+- spin_unlock(&up->port.lock);
++ uart_port_unlock(&up->port);
+ }
+
+ static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
+@@ -364,14 +364,14 @@ static void ma35d1serial_break_ctl(struc
+ unsigned long flags;
+ u32 lcr;
+
+- spin_lock_irqsave(&up->port.lock, flags);
++ uart_port_lock_irqsave(&up->port, &flags);
+ lcr = serial_in(up, MA35_LCR_REG);
+ if (break_state != 0)
+ lcr |= MA35_LCR_BREAK;
+ else
+ lcr &= ~MA35_LCR_BREAK;
+ serial_out(up, MA35_LCR_REG, lcr);
+- spin_unlock_irqrestore(&up->port.lock, flags);
++ uart_port_unlock_irqrestore(&up->port, flags);
+ }
+
+ static int ma35d1serial_startup(struct uart_port *port)
+@@ -441,7 +441,7 @@ static void ma35d1serial_set_termios(str
+ * Ok, we're now changing the port state. Do it with
+ * interrupts disabled.
+ */
+- spin_lock_irqsave(&up->port.lock, flags);
++ uart_port_lock_irqsave(&up->port, &flags);
+
+ up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
+ if (termios->c_iflag & INPCK)
+@@ -475,7 +475,7 @@ static void ma35d1serial_set_termios(str
+
+ serial_out(up, MA35_LCR_REG, lcr);
+
+- spin_unlock_irqrestore(&up->port.lock, flags);
++ uart_port_unlock_irqrestore(&up->port, flags);
+ }
+
+ static const char *ma35d1serial_type(struct uart_port *port)
+@@ -560,9 +560,9 @@ static void ma35d1serial_console_write(s
+ if (up->port.sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+- locked = spin_trylock_irqsave(&up->port.lock, flags);
++ locked = uart_port_trylock_irqsave(&up->port, &flags);
+ else
+- spin_lock_irqsave(&up->port.lock, flags);
++ uart_port_lock_irqsave(&up->port, &flags);
+
+ /*
+ * First save the IER then disable the interrupts
+@@ -576,7 +576,7 @@ static void ma35d1serial_console_write(s
+ serial_out(up, MA35_IER_REG, ier);
+
+ if (locked)
+- spin_unlock_irqrestore(&up->port.lock, flags);
++ uart_port_unlock_irqrestore(&up->port, flags);
+ }
+
+ static int __init ma35d1serial_console_setup(struct console *co, char *options)