summaryrefslogtreecommitdiffstats
path: root/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch
diff options
context:
space:
mode:
Diffstat (limited to 'debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch')
-rw-r--r--debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch128
1 files changed, 128 insertions, 0 deletions
diff --git a/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..90efec4080
--- /dev/null
+++ b/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch
@@ -0,0 +1,128 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:39 +0206
+Subject: [PATCH 022/134] serial: bcm63xx-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>
+Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+Link: https://lore.kernel.org/r/20230914183831.587273-23-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/bcm63xx_uart.c | 22 +++++++++++-----------
+ 1 file changed, 11 insertions(+), 11 deletions(-)
+
+--- a/drivers/tty/serial/bcm63xx_uart.c
++++ b/drivers/tty/serial/bcm63xx_uart.c
+@@ -201,7 +201,7 @@ static void bcm_uart_break_ctl(struct ua
+ unsigned long flags;
+ unsigned int val;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ if (ctl)
+@@ -210,7 +210,7 @@ static void bcm_uart_break_ctl(struct ua
+ val &= ~UART_CTL_XMITBRK_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /*
+@@ -332,7 +332,7 @@ static irqreturn_t bcm_uart_interrupt(in
+ unsigned int irqstat;
+
+ port = dev_id;
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+
+ irqstat = bcm_uart_readl(port, UART_IR_REG);
+ if (irqstat & UART_RX_INT_STAT)
+@@ -353,7 +353,7 @@ static irqreturn_t bcm_uart_interrupt(in
+ estat & UART_EXTINP_DCD_MASK);
+ }
+
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+ return IRQ_HANDLED;
+ }
+
+@@ -451,9 +451,9 @@ static void bcm_uart_shutdown(struct uar
+ {
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ bcm_uart_writel(port, 0, UART_IR_REG);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ bcm_uart_disable(port);
+ bcm_uart_flush(port);
+@@ -470,7 +470,7 @@ static void bcm_uart_set_termios(struct
+ unsigned long flags;
+ int tries;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Drain the hot tub fully before we power it off for the winter. */
+ for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
+@@ -546,7 +546,7 @@ static void bcm_uart_set_termios(struct
+
+ uart_update_timeout(port, new->c_cflag, baud);
+ bcm_uart_enable(port);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /*
+@@ -712,9 +712,9 @@ static void bcm_console_write(struct con
+ /* bcm_uart_interrupt() already took the lock */
+ locked = 0;
+ } else if (oops_in_progress) {
+- locked = spin_trylock(&port->lock);
++ locked = uart_port_trylock(port);
+ } else {
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ locked = 1;
+ }
+
+@@ -725,7 +725,7 @@ static void bcm_console_write(struct con
+ wait_for_xmitr(port);
+
+ if (locked)
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+ local_irq_restore(flags);
+ }
+