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-rw-r--r--debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch118
1 files changed, 118 insertions, 0 deletions
diff --git a/debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch b/debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..7cb8da7d86
--- /dev/null
+++ b/debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch
@@ -0,0 +1,118 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:44:03 +0206
+Subject: [PATCH 046/134] serial: pic32: 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/20230914183831.587273-47-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/pic32_uart.c | 20 ++++++++++----------
+ 1 file changed, 10 insertions(+), 10 deletions(-)
+
+--- a/drivers/tty/serial/pic32_uart.c
++++ b/drivers/tty/serial/pic32_uart.c
+@@ -243,7 +243,7 @@ static void pic32_uart_break_ctl(struct
+ struct pic32_sport *sport = to_pic32_sport(port);
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ if (ctl)
+ pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA),
+@@ -252,7 +252,7 @@ static void pic32_uart_break_ctl(struct
+ pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+ PIC32_UART_STA_UTXBRK);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /* get port type in string format */
+@@ -274,7 +274,7 @@ static void pic32_uart_do_rx(struct uart
+ */
+ max_count = PIC32_UART_RX_FIFO_DEPTH;
+
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+
+ tty = &port->state->port;
+
+@@ -331,7 +331,7 @@ static void pic32_uart_do_rx(struct uart
+
+ } while (--max_count);
+
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ tty_flip_buffer_push(tty);
+ }
+@@ -410,9 +410,9 @@ static irqreturn_t pic32_uart_tx_interru
+ struct uart_port *port = dev_id;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ pic32_uart_do_tx(port);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return IRQ_HANDLED;
+ }
+@@ -580,9 +580,9 @@ static void pic32_uart_shutdown(struct u
+ unsigned long flags;
+
+ /* disable uart */
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ pic32_uart_dsbl_and_mask(port);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ clk_disable_unprepare(sport->clk);
+
+ /* free all 3 interrupts for this UART */
+@@ -604,7 +604,7 @@ static void pic32_uart_set_termios(struc
+ unsigned int quot;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* disable uart and mask all interrupts while changing speed */
+ pic32_uart_dsbl_and_mask(port);
+@@ -672,7 +672,7 @@ static void pic32_uart_set_termios(struc
+ /* enable uart */
+ pic32_uart_en_and_unmask(port);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /* serial core request to claim uart iomem */