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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/0044-serial-owl-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 'debian/patches-rt/0044-serial-owl-Use-port-lock-wrappers.patch')
-rw-r--r--debian/patches-rt/0044-serial-owl-Use-port-lock-wrappers.patch147
1 files changed, 147 insertions, 0 deletions
diff --git a/debian/patches-rt/0044-serial-owl-Use-port-lock-wrappers.patch b/debian/patches-rt/0044-serial-owl-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..fd8dc75013
--- /dev/null
+++ b/debian/patches-rt/0044-serial-owl-Use-port-lock-wrappers.patch
@@ -0,0 +1,147 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:44:01 +0206
+Subject: [PATCH 044/134] serial: owl: 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/20230914183831.587273-45-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/owl-uart.c | 26 +++++++++++++-------------
+ 1 file changed, 13 insertions(+), 13 deletions(-)
+
+--- a/drivers/tty/serial/owl-uart.c
++++ b/drivers/tty/serial/owl-uart.c
+@@ -125,12 +125,12 @@ static unsigned int owl_uart_tx_empty(st
+ u32 val;
+ unsigned int ret;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0;
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return ret;
+ }
+@@ -232,7 +232,7 @@ static irqreturn_t owl_uart_irq(int irq,
+ unsigned long flags;
+ u32 stat;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ stat = owl_uart_read(port, OWL_UART_STAT);
+
+@@ -246,7 +246,7 @@ static irqreturn_t owl_uart_irq(int irq,
+ stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP;
+ owl_uart_write(port, stat, OWL_UART_STAT);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return IRQ_HANDLED;
+ }
+@@ -256,14 +256,14 @@ static void owl_uart_shutdown(struct uar
+ u32 val;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE
+ | OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN);
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ free_irq(port->irq, port);
+ }
+@@ -279,7 +279,7 @@ static int owl_uart_startup(struct uart_
+ if (ret)
+ return ret;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP
+@@ -291,7 +291,7 @@ static int owl_uart_startup(struct uart_
+ val |= OWL_UART_CTL_EN;
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return 0;
+ }
+@@ -311,7 +311,7 @@ static void owl_uart_set_termios(struct
+ u32 ctl;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ ctl = owl_uart_read(port, OWL_UART_CTL);
+
+@@ -371,7 +371,7 @@ static void owl_uart_set_termios(struct
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static void owl_uart_release_port(struct uart_port *port)
+@@ -515,9 +515,9 @@ static void owl_uart_port_write(struct u
+ if (port->sysrq)
+ 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;
+ }
+
+@@ -541,7 +541,7 @@ static void owl_uart_port_write(struct u
+ owl_uart_write(port, old_ctl, OWL_UART_CTL);
+
+ if (locked)
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ local_irq_restore(flags);
+ }