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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:28:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:28:00 +0000
commit3565071f226432336a54d0193d729fa4508a3394 (patch)
tree4cde13f078f84c0a7785d234fd52edce7c90546a /debian/patches-rt/0042-serial-mvebu-uart-Use-port-lock-wrappers.patch
parentAdding upstream version 6.6.15. (diff)
downloadlinux-3565071f226432336a54d0193d729fa4508a3394.tar.xz
linux-3565071f226432336a54d0193d729fa4508a3394.zip
Adding debian version 6.6.15-2.debian/6.6.15-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--debian/patches-rt/0042-serial-mvebu-uart-Use-port-lock-wrappers.patch108
1 files changed, 108 insertions, 0 deletions
diff --git a/debian/patches-rt/0042-serial-mvebu-uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0042-serial-mvebu-uart-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..28b2c3b46e
--- /dev/null
+++ b/debian/patches-rt/0042-serial-mvebu-uart-Use-port-lock-wrappers.patch
@@ -0,0 +1,108 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:59 +0206
+Subject: [PATCH 042/134] serial: mvebu-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>
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+Link: https://lore.kernel.org/r/20230914183831.587273-43-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/mvebu-uart.c | 18 +++++++++---------
+ 1 file changed, 9 insertions(+), 9 deletions(-)
+
+--- a/drivers/tty/serial/mvebu-uart.c
++++ b/drivers/tty/serial/mvebu-uart.c
+@@ -187,9 +187,9 @@ static unsigned int mvebu_uart_tx_empty(
+ unsigned long flags;
+ unsigned int st;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ st = readl(port->membase + UART_STAT);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
+ }
+@@ -249,14 +249,14 @@ static void mvebu_uart_break_ctl(struct
+ unsigned int ctl;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ ctl = readl(port->membase + UART_CTRL(port));
+ if (brk == -1)
+ ctl |= CTRL_SND_BRK_SEQ;
+ else
+ ctl &= ~CTRL_SND_BRK_SEQ;
+ writel(ctl, port->membase + UART_CTRL(port));
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
+@@ -540,7 +540,7 @@ static void mvebu_uart_set_termios(struc
+ unsigned long flags;
+ unsigned int baud, min_baud, max_baud;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
+ STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
+@@ -589,7 +589,7 @@ static void mvebu_uart_set_termios(struc
+ uart_update_timeout(port, termios->c_cflag, baud);
+ }
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static const char *mvebu_uart_type(struct uart_port *port)
+@@ -735,9 +735,9 @@ static void mvebu_uart_console_write(str
+ int locked = 1;
+
+ if (oops_in_progress)
+- locked = spin_trylock_irqsave(&port->lock, flags);
++ locked = uart_port_trylock_irqsave(port, &flags);
+ else
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
+ intr = readl(port->membase + UART_INTR(port)) &
+@@ -758,7 +758,7 @@ static void mvebu_uart_console_write(str
+ }
+
+ if (locked)
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static int mvebu_uart_console_setup(struct console *co, char *options)