diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0019-serial-ar933x-Use-port-lock-wrappers.patch | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/debian/patches-rt/0019-serial-ar933x-Use-port-lock-wrappers.patch b/debian/patches-rt/0019-serial-ar933x-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..61a5d3b1a6 --- /dev/null +++ b/debian/patches-rt/0019-serial-ar933x-Use-port-lock-wrappers.patch @@ -0,0 +1,144 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:36 +0206 +Subject: [PATCH 019/134] serial: ar933x: 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/20230914183831.587273-20-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/ar933x_uart.c | 26 +++++++++++++------------- + 1 file changed, 13 insertions(+), 13 deletions(-) + +--- a/drivers/tty/serial/ar933x_uart.c ++++ b/drivers/tty/serial/ar933x_uart.c +@@ -133,9 +133,9 @@ static unsigned int ar933x_uart_tx_empty + unsigned long flags; + unsigned int rdata; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT; + } +@@ -220,14 +220,14 @@ static void ar933x_uart_break_ctl(struct + container_of(port, struct ar933x_uart_port, port); + unsigned long flags; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + if (break_state == -1) + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_BREAK); + else + ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_BREAK); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + /* +@@ -318,7 +318,7 @@ static void ar933x_uart_set_termios(stru + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* disable the UART */ + ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, +@@ -352,7 +352,7 @@ static void ar933x_uart_set_termios(stru + AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S, + AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + if (tty_termios_baud_rate(new)) + tty_termios_encode_baud_rate(new, baud, baud); +@@ -450,7 +450,7 @@ static irqreturn_t ar933x_uart_interrupt + if ((status & AR933X_UART_CS_HOST_INT) == 0) + return IRQ_NONE; + +- spin_lock(&up->port.lock); ++ uart_port_lock(&up->port); + + status = ar933x_uart_read(up, AR933X_UART_INT_REG); + status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG); +@@ -468,7 +468,7 @@ static irqreturn_t ar933x_uart_interrupt + ar933x_uart_tx_chars(up); + } + +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + + return IRQ_HANDLED; + } +@@ -485,7 +485,7 @@ static int ar933x_uart_startup(struct ua + if (ret) + return ret; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* Enable HOST interrupts */ + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, +@@ -498,7 +498,7 @@ static int ar933x_uart_startup(struct ua + /* Enable RX interrupts */ + ar933x_uart_start_rx_interrupt(up); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + return 0; + } +@@ -632,9 +632,9 @@ static void ar933x_uart_console_write(st + 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); + + /* + * First save the IER then disable the interrupts +@@ -654,7 +654,7 @@ static void ar933x_uart_console_write(st + ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS); + + if (locked) +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + + local_irq_restore(flags); + } |