diff options
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.patch | 147 |
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 000000000..fd8dc7501 --- /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); + } |