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-rw-r--r--debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch124
1 files changed, 124 insertions, 0 deletions
diff --git a/debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch b/debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..4326b333a7
--- /dev/null
+++ b/debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch
@@ -0,0 +1,124 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:48 +0206
+Subject: [PATCH 031/134] serial: jsm: 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/20230914183831.587273-32-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/jsm/jsm_neo.c | 4 ++--
+ drivers/tty/serial/jsm/jsm_tty.c | 16 ++++++++--------
+ 2 files changed, 10 insertions(+), 10 deletions(-)
+
+--- a/drivers/tty/serial/jsm/jsm_neo.c
++++ b/drivers/tty/serial/jsm/jsm_neo.c
+@@ -816,9 +816,9 @@ static void neo_parse_isr(struct jsm_boa
+ /* Parse any modem signal changes */
+ jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+ "MOD_STAT: sending to parse_modem_sigs\n");
+- spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
++ uart_port_lock_irqsave(&ch->uart_port, &lock_flags);
+ neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
+- spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
++ uart_port_unlock_irqrestore(&ch->uart_port, lock_flags);
+ }
+ }
+
+--- a/drivers/tty/serial/jsm/jsm_tty.c
++++ b/drivers/tty/serial/jsm/jsm_tty.c
+@@ -152,14 +152,14 @@ static void jsm_tty_send_xchar(struct ua
+ container_of(port, struct jsm_channel, uart_port);
+ struct ktermios *termios;
+
+- spin_lock_irqsave(&port->lock, lock_flags);
++ uart_port_lock_irqsave(port, &lock_flags);
+ termios = &port->state->port.tty->termios;
+ if (ch == termios->c_cc[VSTART])
+ channel->ch_bd->bd_ops->send_start_character(channel);
+
+ if (ch == termios->c_cc[VSTOP])
+ channel->ch_bd->bd_ops->send_stop_character(channel);
+- spin_unlock_irqrestore(&port->lock, lock_flags);
++ uart_port_unlock_irqrestore(port, lock_flags);
+ }
+
+ static void jsm_tty_stop_rx(struct uart_port *port)
+@@ -176,13 +176,13 @@ static void jsm_tty_break(struct uart_po
+ struct jsm_channel *channel =
+ container_of(port, struct jsm_channel, uart_port);
+
+- spin_lock_irqsave(&port->lock, lock_flags);
++ uart_port_lock_irqsave(port, &lock_flags);
+ if (break_state == -1)
+ channel->ch_bd->bd_ops->send_break(channel);
+ else
+ channel->ch_bd->bd_ops->clear_break(channel);
+
+- spin_unlock_irqrestore(&port->lock, lock_flags);
++ uart_port_unlock_irqrestore(port, lock_flags);
+ }
+
+ static int jsm_tty_open(struct uart_port *port)
+@@ -241,7 +241,7 @@ static int jsm_tty_open(struct uart_port
+ channel->ch_cached_lsr = 0;
+ channel->ch_stops_sent = 0;
+
+- spin_lock_irqsave(&port->lock, lock_flags);
++ uart_port_lock_irqsave(port, &lock_flags);
+ termios = &port->state->port.tty->termios;
+ channel->ch_c_cflag = termios->c_cflag;
+ channel->ch_c_iflag = termios->c_iflag;
+@@ -261,7 +261,7 @@ static int jsm_tty_open(struct uart_port
+ jsm_carrier(channel);
+
+ channel->ch_open_count++;
+- spin_unlock_irqrestore(&port->lock, lock_flags);
++ uart_port_unlock_irqrestore(port, lock_flags);
+
+ jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n");
+ return 0;
+@@ -307,7 +307,7 @@ static void jsm_tty_set_termios(struct u
+ struct jsm_channel *channel =
+ container_of(port, struct jsm_channel, uart_port);
+
+- spin_lock_irqsave(&port->lock, lock_flags);
++ uart_port_lock_irqsave(port, &lock_flags);
+ channel->ch_c_cflag = termios->c_cflag;
+ channel->ch_c_iflag = termios->c_iflag;
+ channel->ch_c_oflag = termios->c_oflag;
+@@ -317,7 +317,7 @@ static void jsm_tty_set_termios(struct u
+
+ channel->ch_bd->bd_ops->param(channel);
+ jsm_carrier(channel);
+- spin_unlock_irqrestore(&port->lock, lock_flags);
++ uart_port_unlock_irqrestore(port, lock_flags);
+ }
+
+ static const char *jsm_tty_type(struct uart_port *port)