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-rw-r--r--debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch148
1 files changed, 148 insertions, 0 deletions
diff --git a/debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch b/debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..06518e8460
--- /dev/null
+++ b/debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch
@@ -0,0 +1,148 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:50 +0206
+Subject: [PATCH 033/134] serial: lpc32xx_hs: 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/20230914183831.587273-34-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/lpc32xx_hs.c | 26 +++++++++++++-------------
+ 1 file changed, 13 insertions(+), 13 deletions(-)
+
+--- a/drivers/tty/serial/lpc32xx_hs.c
++++ b/drivers/tty/serial/lpc32xx_hs.c
+@@ -140,15 +140,15 @@ static void lpc32xx_hsuart_console_write
+ if (up->port.sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+- locked = spin_trylock(&up->port.lock);
++ locked = uart_port_trylock(&up->port);
+ else
+- spin_lock(&up->port.lock);
++ uart_port_lock(&up->port);
+
+ uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
+ wait_for_xmit_empty(&up->port);
+
+ if (locked)
+- spin_unlock(&up->port.lock);
++ uart_port_unlock(&up->port);
+ local_irq_restore(flags);
+ }
+
+@@ -298,7 +298,7 @@ static irqreturn_t serial_lpc32xx_interr
+ struct tty_port *tport = &port->state->port;
+ u32 status;
+
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+
+ /* Read UART status and clear latched interrupts */
+ status = readl(LPC32XX_HSUART_IIR(port->membase));
+@@ -333,7 +333,7 @@ static irqreturn_t serial_lpc32xx_interr
+ __serial_lpc32xx_tx(port);
+ }
+
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ return IRQ_HANDLED;
+ }
+@@ -404,14 +404,14 @@ static void serial_lpc32xx_break_ctl(str
+ unsigned long flags;
+ u32 tmp;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+ if (break_state != 0)
+ tmp |= LPC32XX_HSU_BREAK;
+ else
+ tmp &= ~LPC32XX_HSU_BREAK;
+ writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /* port->lock is not held. */
+@@ -421,7 +421,7 @@ static int serial_lpc32xx_startup(struct
+ unsigned long flags;
+ u32 tmp;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ __serial_uart_flush(port);
+
+@@ -441,7 +441,7 @@ static int serial_lpc32xx_startup(struct
+
+ lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ retval = request_irq(port->irq, serial_lpc32xx_interrupt,
+ 0, MODNAME, port);
+@@ -458,7 +458,7 @@ static void serial_lpc32xx_shutdown(stru
+ u32 tmp;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+ LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
+@@ -466,7 +466,7 @@ static void serial_lpc32xx_shutdown(stru
+
+ lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ free_irq(port->irq, port);
+ }
+@@ -491,7 +491,7 @@ static void serial_lpc32xx_set_termios(s
+
+ quot = __serial_get_clock_div(port->uartclk, baud);
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Ignore characters? */
+ tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+@@ -505,7 +505,7 @@ static void serial_lpc32xx_set_termios(s
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ /* Don't rewrite B0 */
+ if (tty_termios_baud_rate(termios))